Affinage

SLC12A2

Solute carrier family 12 member 2 · UniProt P55011

Length
1212 aa
Mass
131.4 kDa
Annotated
2026-04-28
100 papers in source corpus 42 papers cited in narrative 42 extracted findings

Mechanistic narrative

Synthesis pass · prose summary of the discoveries below

SLC12A2 encodes NKCC1, an electroneutral Na⁺/K⁺/2Cl⁻ cotransporter that operates as a homodimer with an LeuT-fold transmembrane core containing discrete binding sites for Na⁺, K⁺, and two Cl⁻ ions, and that undergoes alternating-access conformational changes to couple ion translocation (PMID:31367042, PMID:32081947, PMID:36239040). Transport activity is activated by WNK–SPAK/OSR1 kinase-mediated phosphorylation of N-terminal threonines and suppressed by PP1-type phosphatases, with the phosphoregulatory domain communicating with the C-terminal domain to control conformational transitions; additional regulation occurs through N-glycosylation-dependent surface targeting and aldosterone-mediated protein stabilization (PMID:12740379, PMID:22032326, PMID:35585053, PMID:26351455, PMID:24173102). Physiologically, NKCC1 localizes to basolateral membranes of secretory epithelia—including airway, colon, sweat gland, and mammary gland—where it drives transepithelial Cl⁻ secretion, and to the apical membrane of choroid plexus epithelium where it mediates CSF K⁺ clearance and volume homeostasis; in neurons, NKCC1 accumulates intracellular Cl⁻ to sustain depolarizing GABA signaling critical for progenitor proliferation and circuit maturation (PMID:11443061, PMID:9038823, PMID:33469018, PMID:23015452, PMID:34058387). Loss-of-function mutations in SLC12A2 cause sensorineural hearing loss and neurodevelopmental disorders in humans and mice, linked to defective endolymph homeostasis and impaired neuronal Cl⁻ regulation (PMID:10401008, PMID:32658972).

Mechanistic history

Synthesis pass · year-by-year structured walk · 19 steps
  1. 1997 Medium

    Initial molecular characterization defined the SLC12A2 gene structure, tissue-specific promoter usage, and a brain-specific splice variant lacking a PKA phosphorylation site, establishing the framework for understanding isoform-specific regulation.

    Evidence Genomic cloning, RNase protection, primer extension, RT-PCR of splice variants

    PMID:9357771

    Open questions at the time
    • Direct functional consequence of exon 21 exclusion on transport not tested
    • PKA-mediated regulation of the full-length isoform not demonstrated in vivo
  2. 1997 High

    Localization of NKCC1 to the apical choroid plexus and neuronal cell bodies established its dual epithelial-neuronal expression pattern, implying roles in both CSF ion homeostasis and neuronal Cl⁻ regulation.

    Evidence Immunocytochemistry, confocal microscopy, ⁸⁶Rb⁺ transport in polarized choroid plexus cells

    PMID:9038823

    Open questions at the time
    • In vivo functional consequence of choroid plexus NKCC1 not yet demonstrated
    • Mechanism of apical vs. basolateral sorting unknown
  3. 1998 High

    Reconstitution kinetics revealed that NKCC1 activity is governed primarily by intracellular Cl⁻ concentration rather than cell volume, distinguishing it from NKCC2 and defining the sensory logic of cotransporter regulation.

    Evidence Stable HEK-293 expression, ⁸⁶Rb uptake kinetics, chimeric constructs, ion substitution

    PMID:9556622

    Open questions at the time
    • Molecular sensor for intracellular Cl⁻ not identified
    • Structural basis of isoform-specific kinetic differences unknown at this time
  4. 1999 High

    Positional cloning of deafness-causing Slc12a2 mutations in mice established NKCC1 as essential for endolymph K⁺ recycling and cochlear function, providing the first in vivo loss-of-function phenotype.

    Evidence Positional cloning, mutation identification, phenotyping of sy/sy(ns) deaf mice

    PMID:10401008

    Open questions at the time
    • Precise cell type within stria vascularis mediating the phenotype not resolved
    • Human disease mutations not yet identified at this time
  5. 2001 High

    NKCC1 knockout airway studies demonstrated that basolateral NKCC1 is the principal Cl⁻ entry pathway for agonist-stimulated anion secretion, with HCO₃⁻ secretion partially compensating in its absence.

    Evidence NKCC1 KO mice, Ussing chamber short-circuit current, bumetanide pharmacology

    PMID:11443061

    Open questions at the time
    • Relative contribution of NKCC1 vs. other basolateral Cl⁻ pathways in adult airways not quantified
    • Compensatory HCO₃⁻ mechanism not molecularly characterized
  6. 2003 High

    Identification of SPAK/PASK as the direct kinase phosphorylating N-terminal threonines of NKCC1 established the core activating kinase–cotransporter axis, with constitutive SPAK–NKCC1 binding and kinase/phosphatase balance controlling activity.

    Evidence Co-IP, ³²P phosphorylation, dominant-negative PASK, ⁸⁶Rb uptake, calyculin A rescue in HEK cells

    PMID:12740379

    Open questions at the time
    • Upstream kinase activating SPAK not yet connected
    • Identity of relevant phosphatase not established
  7. 2005 High

    Multiple tissue-specific studies—sweat gland, juxtaglomerular cells—confirmed basolateral NKCC1 as essential for secretory NaCl entry and revealed an unexpected role suppressing basal renin release, broadening the physiological scope of the transporter.

    Evidence Immunoelectron microscopy (sweat gland), NKCC1 KO mice + patch-clamp + renin assay (JG cells)

    PMID:15843440 PMID:16106034

    Open questions at the time
    • How Cl⁻ accumulation mechanistically suppresses renin exocytosis not delineated
    • Relevance of NKCC1 in human sweat disorders not tested
  8. 2007 High

    In native human colonic crypts, cholinergic stimulation was shown to trigger a dynamic cycle of NKCC1 membrane recruitment, activation, EGFR-dependent internalization, lysosomal degradation, and re-synthesis, revealing post-translational trafficking as a major regulatory layer.

    Evidence Human colonic crypt imaging, ⁸⁶Rb uptake, tyrphostin-AG1478 EGFR inhibitor, cycloheximide, chloroquine

    PMID:17478539

    Open questions at the time
    • EGFR phosphorylation site on NKCC1 or adaptor not identified
    • Whether this trafficking cycle operates in non-colonic epithelia unknown
  9. 2009 High

    Zebrafish nkcc1 loss-of-function confirmed a conserved requirement for NKCC1 in endolymph volume regulation, extending the cochlear phenotype from mouse and establishing evolutionary conservation.

    Evidence ENU mutagenesis, morpholino rescue of splicing defect, otic vesicle volume measurement

    PMID:19633174

    Open questions at the time
    • Specific ionic mechanism by which NKCC1 drives endolymph volume in zebrafish not resolved
  10. 2012 High

    Genetic placement of SPAK/OSR1 downstream of WNK1 and upstream of NKCC1 via double-knockin ES cells completed the WNK–SPAK/OSR1–NKCC1 signaling cascade, showing SPAK/OSR1 are both necessary and sufficient kinases for NKCC1 activation.

    Evidence Double-knockin ES cells (SPAK/OSR1 cannot be activated by WNK1), phospho-specific antibodies, ion transport

    PMID:22032326

    Open questions at the time
    • Whether other WNK family members contribute differentially in specific tissues not resolved
    • Feedback from SPAK/OSR1 onto WNK activity mechanistically unexplained
  11. 2012 High

    NKCC1 knockdown in neonatal subventricular zone progenitors demonstrated that NKCC1-mediated Cl⁻ accumulation underlies depolarizing GABA responses required for neural progenitor proliferation and dendritic arborization, with pharmacological GABA_A rescue confirming the mechanism.

    Evidence In vivo shRNA electroporation, Ki67 staining, Ca²⁺ imaging, dendritic morphology, pentobarbital rescue

    PMID:23015452

    Open questions at the time
    • Whether NKCC1 also affects migration of SVZ-derived neuroblasts not tested
    • Long-term circuit consequences of neonatal NKCC1 loss not characterized
  12. 2015 Medium

    N-glycosylation was shown to be required for NKCC1 plasma membrane targeting and transport function, with glycan biosynthesis or maturation inhibition eliminating surface NKCC1 and cotransport.

    Evidence Tunicamycin, swainsonine, kifunensine treatment, surface biotinylation, ⁸⁶Rb uptake

    PMID:26351455

    Open questions at the time
    • Specific glycosylation sites critical for trafficking not mapped by mutagenesis
    • Only tested in one cell type
  13. 2017 High

    Discovery of a physical NKCC1–Cofilin-1 interaction linked NKCC1 to actin cytoskeletal remodeling and glioblastoma cell migration via RhoA/Rac1 signaling, expanding NKCC1 function beyond ion transport.

    Evidence Co-IP, siRNA knockdown, F-actin staining, Rho-GTPase activity, migration assay, intracranial mouse model

    PMID:28679472

    Open questions at the time
    • Whether ion transport activity is required for migration effect or whether it is a scaffolding function unknown
    • Reciprocal effect of Cofilin-1 on NKCC1 transport not tested
  14. 2019 High

    The first cryo-EM structure of NKCC1 (zebrafish) defined the LeuT-fold architecture, ion-binding sites for Na⁺, K⁺, and 2Cl⁻, and the ion-translocation pathway, providing the atomic framework for understanding transport mechanism and CCC family function.

    Evidence Single-particle cryo-EM, MD simulations, mutagenesis, functional transport assays

    PMID:31367042

    Open questions at the time
    • Only one conformational state captured
    • Drug-binding sites not resolved
  15. 2019 High

    Identification of NKCC1 in a complex with the leucine transporter LAT1 revealed that NKCC1 suppresses mTORC1 signaling and couples cell volume to cell mass regulation, establishing a non-canonical growth-regulatory role.

    Evidence Co-IP, CRISPR KO, siRNA, mTORC1 signaling assays, colonic organoids, mouse colon KO

    PMID:31067471

    Open questions at the time
    • Direct vs. indirect nature of NKCC1–LAT1 interaction not structurally resolved
    • Whether ion transport activity is required for mTORC1 suppression not determined
  16. 2020 High

    Human NKCC1 cryo-EM structure in a partially loaded inward-open state revealed dimeric assembly, broken α-helical geometry at ion-binding sites on TM1/TM6, and distinct entryway/exit routes for different ions, refining the transport cycle model.

    Evidence Single-particle cryo-EM of human NKCC1

    PMID:32081947

    Open questions at the time
    • Outward-facing state not captured in this study
    • Ion occupancy at individual sites uncertain
  17. 2020 High

    Functional characterization of de novo SLC12A2 mutations from children with neurodevelopmental disorders and hearing loss established loss-of-function as the pathogenic mechanism in human disease, confirming NKCC1 haploinsufficiency as disease-causing.

    Evidence Xenopus oocyte expression, ⁸⁶Rb uptake for multiple patient variants, trio exome sequencing

    PMID:32658972

    Open questions at the time
    • Genotype–phenotype correlations across variant types not fully established
    • Whether heterozygous loss is sufficient or requires second hit unknown
  18. 2022 High

    Capture of NKCC1 in outward-facing, occluded, and drug-bound conformations completed the structural catalog of the transport cycle, revealed bumetanide/furosemide binding pockets, and showed that N-terminal phosphoregulatory domain–C-terminal domain interaction controls conformational switching.

    Evidence Cryo-EM in multiple conformational/drug-bound states, functional mutagenesis, MD simulations

    PMID:35585053 PMID:36239040 PMID:36306358

    Open questions at the time
    • Full transport cycle with all ions simultaneously resolved not achieved
    • How phosphorylation physically disrupts N-term–C-term interaction not structurally captured
  19. 2023 High

    Choroid plexus NKCC1 was shown to be activated by blood-derived K⁺ to clear CSF and prevent post-hemorrhagic ventriculomegaly; a phosphodeficient mutant failed to rescue, demonstrating that phosphorylation-dependent activation is required for CSF homeostasis in disease.

    Evidence AAV-mediated ChP-targeted NKCC1 overexpression/phosphodeficient mutant, Ca²⁺ imaging, ventriculometry, CSF K⁺ measurement

    PMID:36893755

    Open questions at the time
    • Identity of the kinase activated by K⁺-triggered Ca²⁺ signals in choroid plexus not confirmed
    • Whether NKCC1-targeted therapy is viable in human post-hemorrhagic hydrocephalus untested

Open questions

Synthesis pass · forward-looking unresolved questions
  • Outstanding questions include the structural basis of phosphorylation-induced N-terminal–C-terminal domain dissociation, the identity of the Cl⁻ sensor that activates WNK signaling, whether NKCC1's mTORC1-suppressive and migration-promoting roles require ion transport or scaffolding, and the molecular mechanisms underlying NKCC1's role in goblet cell mucus granule exocytosis.
  • Structural visualization of phosphorylated vs. dephosphorylated regulatory domain interaction
  • Intracellular Cl⁻ sensor identity linking Cl⁻ to WNK activation
  • Separation of transport-dependent vs. scaffolding functions in migration and growth signaling

Mechanism profile

Synthesis pass · controlled-vocabulary classification · explore literature graph →
Molecular activity
GO:0005215 transporter activity 6
Localization
GO:0005886 plasma membrane 6
Pathway
R-HSA-162582 Signal Transduction 4 R-HSA-382551 Transport of small molecules 4 R-HSA-112316 Neuronal System 3
Partners
CFL1OSR1SLC7A5SPAKTRPV1WNK1
Complex memberships
NKCC1 homodimer

Evidence

Reading pass · 42 per-paper findings extracted from the source corpus
Year Finding Method Journal Conf PMIDs
2019 Cryo-EM structure of zebrafish NKCC1 defines the architecture of the CCC family, reveals the ion-translocation pathway, ion-binding sites (Na+, K+, 2Cl-), key residues for transport activity, and how cytosolic and transmembrane domains communicate; structural analyses combined with functional characterizations and computational studies establish mechanisms of ion selectivity, coupling, and translocation. Single-particle cryo-EM, functional transport assays, computational (MD) simulations, mutagenesis Nature High 31367042
2020 Cryo-EM structure of human NKCC1 in a partially loaded, inward-open state reveals a dimeric assembly; TM1 and TM6 helices break α-helical geometry at ion-binding sites; multiple extracellular entryways and intracellular exits are identified, suggesting K+, Na+, and Cl- may traverse along distinct routes. Single-particle cryo-EM Nature communications High 32081947
2021 Cryo-EM structures of human NKCC1 and mouse KCC2 at near-atomic resolution identify essential residues for ion transport and reveal mechanisms by which N-terminal phosphorylation regulates transport activity. Cryo-EM, computational analysis, functional characterization Communications biology High 33597714
2022 Cryo-EM structure of NKCC1 in an outward-facing conformation shows bumetanide wedged into a pocket in the extracellular ion translocation pathway; comparison with inward-facing structures defines the translocation pathway and conformational changes for ion translocation; an N-terminal phosphoregulatory domain interacts with the C-terminal domain, suggesting (de)phosphorylation regulates NKCC1 by tuning this domain association. Single-particle cryo-EM, functional studies, mutagenesis Nature communications High 35585053
2022 2.6 Å cryo-EM structure of human NKCC1 in substrate-loaded, occluded inward-facing state reveals Cl- binding at Cl1 site bridges scaffold and bundle domains via K+; Cl- at Cl2 site plays a structural role analogous to conserved glutamate in SLC6 transporters; a putative Na+ release pathway along TM5 coupled to the Cl2 site is identified and supported by functional studies and MD simulations. Cryo-EM (2.6 Å), functional assays in mammalian cells, MD simulations The EMBO journal High 36239040
2022 Four cryo-EM structures of human NKCC1 (apo and bound to bumetanide or furosemide) reveal two drug-binding sites at transmembrane and cytosolic C-terminal domains; an inhibition mechanism involving coupled movement between cytosolic and transmembrane domains is delineated; the C-terminal domain is implicated in long-range conformational coupling. Single-particle cryo-EM, functional studies Science advances High 36306358
2003 PASK/SPAK kinase directly phosphorylates two regulatory threonines on the N-terminal domain of NKCC1 and activates cotransport; dominant-negative PASK markedly reduces NKCC1 phosphorylation and activity; co-immunoprecipitation confirms constitutive PASK–NKCC1 binding in HEK cells; phosphatase inhibitor calyculin A rescues activity, indicating kinase/phosphatase balance controls NKCC1. Dominant-negative overexpression, co-immunoprecipitation, 32Pi phosphorylation assay, ion transport assay (86Rb uptake) The Journal of biological chemistry High 12740379
2012 SPAK and OSR1 are essential upstream kinases for NKCC1 phosphorylation and activation; double-knockin ES cells where SPAK/OSR1 cannot be activated by WNK1 show complete loss of NKCC1 phosphorylation and activation; SPAK/OSR1 activity also significantly influences WNK kinase activity (feedback). Double-knockin ES cells (loss-of-function genetic approach), phospho-specific antibodies, ion transport assay The Biochemical journal High 22032326
2012 Estradiol increases protein levels of SPAK and OSR1 in the neonatal hypothalamus in a transcription-dependent manner; SPAK/OSR1 upregulation mediates estradiol-enhanced NKCC1 phosphorylation; antisense knockdown of SPAK (and to a lesser extent OSR1) blocks estradiol-enhanced NKCC1 phosphorylation and GABA-induced Ca2+ influx. In vivo antisense oligonucleotide knockdown, Western blot with phospho-specific antibodies, calcium imaging The Journal of neuroscience High 22238094
2011 IL-6 autocrine signaling in axotomized sensory neurons activates NKCC1 via JAK signaling and IL-6 receptor upregulation, leading to NKCC1 phosphorylation and Cl- accumulation that supports neurite regrowth; IL-6 neutralization or IL-6-/- mice prevent NKCC1 phosphorylation and Cl- accumulation. IL-6 knockout mice, receptor-blocking antibodies, pharmacological JAK inhibition, functional Cl- accumulation assay, neurite growth assay The Journal of neuroscience High 21940443
1999 Point mutations in Slc12a2 (encoding basolateral Na-K-Cl cotransporter NKCC1) cause deafness and abnormal endolymph production in sy and sy(ns) mice, establishing NKCC1 as an essential component of K+ recycling in the cochlea. Positional cloning, mutation identification, mouse phenotyping (deaf mutant) Human molecular genetics High 10401008
2009 Loss-of-function mutations in zebrafish nkcc1 (slc12a2) cause collapse of the otic vesicle (endolymph fluid loss) and over-inflation of the swim bladder, establishing NKCC1 as required for endolymph volume regulation; morpholino rescue of splicing defect ameliorates ear volume collapse. Forward genetics (ENU mutagenesis), Sanger sequencing, morpholino rescue Development High 19633174
1997 BSC2/NKCC1 protein localizes to the apical surface of choroid plexus epithelium and to neuronal cell bodies/dendrites; apical localization in choroid plexus is confirmed by 86Rb+ uptake in cells grown on permeable filters and confocal microscopy, suggesting a role in CSF K+ homeostasis. Immunocytochemistry, confocal microscopy, 86Rb+ transport assay on polarized epithelial cells The American journal of physiology High 9038823
2021 NKCC1 in the choroid plexus mediates CSF K+ clearance during mouse early postnatal development; overexpression of NKCC1 in choroid plexus increases CSF K+ clearance and reduces circulating CSF; in an obstructive hydrocephalus model, choroid plexus-specific NKCC1 overexpression reduces ventriculomegaly. AAV-mediated gene overexpression in choroid plexus, CSF [K+] measurement, MRI ventriculometry, mouse hydrocephalus model Nature communications High 33469018
2023 Intraventricular blood increases CSF [K+] and triggers cytosolic calcium activity in choroid plexus epithelial cells, followed by NKCC1 activation; AAV-mediated ChP-targeted NKCC1 overexpression prevents blood-induced ventriculomegaly; phosphodeficient NKCC1-NT51 mutant fails to mitigate ventriculomegaly, demonstrating that phosphorylation-dependent NKCC1 activation is required for CSF clearance. AAV gene delivery, phosphodeficient mutant (loss-of-function), calcium imaging, ventriculometry, CSF K+ measurement Neuron High 36893755
2016 A gain-of-function missense variant p.Y199C in the N-terminal regulatory domain of SLC12A2/NKCC1 increases Cl--dependent, bumetanide-sensitive cotransporter activity even under hypotonicity (conditions where wild-type is normally silent), identified in human schizophrenia patients. Xenopus oocyte ion transport assay (Cl--dependent 86Rb uptake), patient sequencing Journal of psychiatric research High 26955005
2020 De novo SLC12A2 mutations identified in children with neurodevelopmental disorders and sensorineural hearing loss all reduce cotransporter function when expressed in Xenopus laevis oocytes, establishing loss-of-function as the pathogenic mechanism. Xenopus oocyte expression assay, trio exome sequencing Brain High 32658972
2017 NKCC1 interacts with actin-regulatory protein Cofilin-1 and regulates its membrane localization; NKCC1 knockdown decreases F-actin content and reduces active RhoA and Rac1, thereby decreasing glioblastoma cell migration. Co-immunoprecipitation (NKCC1–Cofilin-1 interaction), siRNA knockdown, F-actin staining, Rho-GTPase activity assay, in vitro migration assay, intracranial mouse model EBioMedicine High 28679472
2019 NKCC1 (SLC12A2) is present in a complex with the leucine transporter LAT1; NKCC1 depletion enhances LAT1 activity, Akt and Erk activation, and mTORC1 activation, reduces intracellular Na+ and cell volume/mass, and stimulates cell proliferation, establishing NKCC1 as a suppressor of mTORC1 that links cell volume to cell mass regulation. Co-immunoprecipitation (NKCC1–LAT1 complex), NKCC1 siRNA/CRISPR deletion, mTORC1 signaling assays, ion flux measurements, colonic organoids, mouse colon KO Cell reports High 31067471
2012 NKCC1 knockdown in neonatal mouse subventricular zone neural progenitor cells reduces GABA-induced depolarization and Ca2+ responses, decreases proliferative Ki67+ progenitors by ~70%, reduces newborn neuron density by ~60%, and causes truncated dendritic arborization; GABAA agonist pentobarbital rescues proliferation, confirming NKCC1 acts via GABAA receptor depolarization. In vivo electroporation of shRNA, Ki67 immunostaining, calcium imaging, dendritic morphology analysis, pharmacological rescue The Journal of neuroscience High 23015452
2017 NKCC1 promotes GABA-mediated depolarization in Cajal-Retzius neurons; genetic deletion or pharmacological blockade of NKCC1 in vitro and in vivo rescues Cajal-Retzius neurons from apoptosis via blockade of p75NTR receptor signaling pathway. NKCC1 genetic knockout mice, in vitro pharmacological blockade (bumetanide), p75NTR pathway analysis, apoptosis assays Cerebral cortex High 26819276
2008 AVP-induced cell swelling in inner medullary collecting duct requires basolateral NaCl uptake via NKCC1; bumetanide abolishes AVP-induced cell height increase; NKCC1 knockout mice lack AVP-induced cell swelling; myosin II also contributes via actin cytoskeleton reorganization. NKCC1 knockout mice, quantitative video microscopy, bumetanide pharmacology, immunocytochemistry, blebbistatin inhibition American journal of physiology. Renal physiology High 18417545
2002 NKCC1 is expressed on the basolateral membrane of mammary epithelial cells; NKCC1-/- mice show delayed ductal outgrowth and increased branching morphogenesis during virgin development in a cell-autonomous manner (demonstrated by transplantation); loss of NKCC1 impairs lactation function. NKCC1 knockout mice, mammary gland transplantation (cell-autonomous test), immunolocalization Molecular endocrinology High 12040017
2005 NKCC1 is expressed on the basolateral membrane of secretory coil cells of sweat glands (rat, mouse, human) and is responsible for bumetanide-sensitive NaCl secretion in sweat glands; NKCC2 is absent; basolateral NKCC1 mediates NaCl entry for fluid secretion. RT-PCR, Western blot, immunoperoxidase, immunoelectron microscopy American journal of physiology. Cell physiology High 15843440
2005 NKCC1 in juxtaglomerular granular cells directly suppresses basal renin release; furosemide stimulates renin release from wild-type JG cells (measured by patch-clamp membrane capacitance and primary culture assay) but not from NKCC1-deficient cells; NKCC1-/- mice have elevated plasma renin. NKCC1 knockout mice, patch-clamp (membrane capacitance), primary JG cell culture renin release assay American journal of physiology. Renal physiology High 16106034
2001 NKCC1 on the basolateral membrane is required for large UTP-stimulated anion secretory responses in mouse airways; NKCC1-/- neonatal trachea has reduced basal short-circuit current; HCO3- secretion compensates for reduced Cl- secretion in knockout airways. NKCC1 knockout mice, Ussing chamber ion transport assay, bumetanide pharmacology American journal of physiology. Cell physiology High 11443061
1997 The Slc12a2 gene encodes a cotransporter with 27 exons and tissue-specific transcription initiation; a brain-specific alternatively spliced variant lacking exon 21 (encoding 16 amino acids of the C-terminal tail) loses the single PKA consensus phosphorylation site, suggesting splice-variant-specific regulation. Genomic cloning, RNase protection assay, primer extension, luciferase reporter transfection, RT-PCR of splice variants The American journal of physiology Medium 9357771
2012 NKCC1 upregulation in hypothalamic paraventricular nucleus presympathetic neurons causes depolarizing shift in GABA reversal potential and disrupts GABAergic inhibition in spontaneously hypertensive rats; NKCC1 inhibition normalizes EGABA; increased N-glycosylation of NKCC1 contributes to its enhanced activity in hypertension. Gramicidin perforated-patch clamp (EGABA measurement), NKCC1 inhibitor bumetanide, N-glycosylation inhibition, Western blot The Journal of neuroscience High 22723696
2013 Aldosterone upregulates NKCC1 protein expression rapidly and independently of mRNA changes, by increasing protein stability (reducing ubiquitination) via mineralocorticoid receptors; proteasome inhibitor MG132 and cycloheximide experiments confirm post-translational stabilization mechanism. HT-29 cell pharmacology, cycloheximide chase, MG132 (proteasome inhibitor), eplerenone (mineralocorticoid receptor antagonist), Western blot American journal of physiology. Cell physiology Medium 24173102
2017 The ubiquitin ligase Nedd4L indirectly suppresses NKCC1 protein abundance in mouse distal colon; conditional intestinal Nedd4L knockout leads to increased NKCC1 protein and elevated NKCC1-dependent short-circuit current; no direct Nedd4L–NKCC1 co-immunoprecipitation detected, indicating indirect regulation. Conditional knockout mice (Nedd4L;Vil-Cre), Ussing chamber Isc, Western blot, co-IP (negative result) The Journal of biological chemistry Medium 28087701
2007 NKCC1 protein localizes to the plasma membrane at the growth cone during NGF-induced neurite outgrowth in PC12D cells; NKCC1 knockdown by RNAi drastically reduces NGF-induced neurite outgrowth; NKCC1 expression is upregulated by NGF. RNAi knockdown, EGFP-NKCC1 live imaging (localization), neurite length measurement Biochemical and biophysical research communications Medium 17548052
2007 In native human colonic epithelium, cholinergic Ca2+ signals initiate NKCC1 recruitment to basolateral membranes, followed by activation, internalization, lysosomal degradation, and re-expression over a 4-hour cycle; internalization requires EGFR kinase activity; cAMP (forskolin) sustains NKCC1 activity without internalization; co-stimulation prolongs the cycle. Human colonic crypt imaging, BCECF/Fura-2/calcein fluorescence, bumetanide-sensitive 86Rb uptake, EGFR inhibitor (tyrphostin-AG1478), cycloheximide, chloroquine The Journal of physiology High 17478539
2015 N-glycosylation of NKCC1 is required for its plasma membrane targeting and transport function; inhibition of N-glycan biosynthesis (tunicamycin) nearly abolishes surface NKCC1 and cotransport; inhibition of N-glycan maturation (swainsonine/kifunensine) eliminates functional complex N-glycosylated NKCC1 from the plasma membrane. Tunicamycin, swainsonine, kifunensine treatment, surface biotinylation, 86Rb uptake functional assay International journal of cell biology Medium 26351455
2022 NKCC1 in microglia regulates baseline and reactive microglial morphology, process recruitment to injury sites, and volume adaptation via membrane conductance in a cell-autonomous manner; microglial NKCC1 deficiency leads to NLRP3 inflammasome priming and increased IL-1β production; NKCC1 microglial KO mice show worse outcomes after experimental stroke. Conditional microglial NKCC1 knockout, morphology analysis, NLRP3/IL-1β assay, experimental stroke model, electrophysiology PLoS biology High 35085235
2018 TRPV1 activation by capsaicin or hyperosmotic solution stimulates NKCC1 phosphorylation and ion transport in lens epithelium via ERK1/2 and WNK kinase signaling; TRPV1-/- lenses lack NKCC1 phosphorylation and Rb+ uptake responses; WNK inhibitor WNK463 prevents NKCC1 phosphorylation; ERK acts upstream of WNK in the signaling cascade. TRPV1 knockout mice, Rb+ uptake assay, NKCC1 phosphorylation (Western blot), MEK/ERK inhibitor (U0126), WNK inhibitor (WNK463), TRPV1 agonist/antagonist American journal of physiology. Cell physiology High 30207782
2005 Six1 and Six4 homeobox transcription factors directly bind multiple sites in the Slc12a2 promoter; gel-retardation assays show distinct DNA-binding specificities between Six1 and Six4; Slc12a2 expression is reduced in developing dorsal root ganglia of Six1-/-/Six4-/- double knockout mice. Gel-retardation assay (EMSA), in situ hybridization in double-KO mice The FEBS journal Medium 15955062
2011 NKCC1 phosphorylation correlates with activation and stimulation of ion transport; kinase inhibitors reduce both phosphorylation and activity of NKCC1 and NKCC2A; calyculin A (phosphatase inhibitor) increases phosphorylation but only slightly stimulates NKCC1 and inhibits NKCC2A, suggesting phosphorylation of N-terminal domain sets transport capacity but final activity depends on additional factors. Stably expressing HEK-293 cells, 86Rb uptake, phospho-specific antibodies, calyculin A and kinase inhibitor pharmacology PloS one Medium 21464992
2019 Novel human SLC12A2/NKCC1 mutations (DFX and Kilquist homozygous deletion) impair goblet cell mucus granule exocytosis, leading to secretion of intact granules into the colonic lumen; loss of NKCC1 or DFX expression aggravates inflammatory response to Citrobacter rodentium infection and decreases claudin-2 expression. Mouse model of NKCC1-DFX mutation, electron microscopy, immunostaining, FISH, Citrobacter infection model, multiplex cytokine assay Cellular and molecular gastroenterology and hepatology High 31655271
2020 In a Drosophila NGLY1-deficiency model, Ncc69 (NKCC1/2 ortholog) is the top genetic modifier; in NGLY1-/- mouse cells, NKCC1 has altered average molecular weight (consistent with N-glycosylation defect) and reduced cotransporter function, linking NKCC1 misregulation to defects in secretory epithelium function in NGLY1 deficiency. Drosophila genetic screen, NGLY1-/- mouse cells, functional NKCC1 assay, molecular weight analysis eLife Medium 33315011
2009 NKCC1 mediates vascular smooth muscle cell contraction; bumetanide inhibits myogenic tone and agonist-induced contractions in wild-type mesenteric arteries but is completely without effect in NKCC1-/- arteries, demonstrating that NKCC1 is the relevant bumetanide target in VSMC excitation-contraction coupling; effect is independent of nitric oxide. NKCC1 knockout mice, mesenteric artery myography, NOS inhibition (L-NAME) Biochemical and biophysical research communications High 19150334
2021 AAV-mediated neuron-specific NKCC1 knockdown restores intracellular chloride concentration, GABA inhibitory efficacy, and neuronal network dynamics in Ts65Dn Down syndrome mice in vitro and ex vivo, and rescues cognitive deficits in behavioral tasks in vivo. AAV-RNAi in vivo, intracellular Cl- measurement, electrophysiology, behavioral assays in Ts65Dn mice Molecular therapy High 34058387
1998 NKCC1 and NKCC2 have distinct kinetic properties: NKCC2A has ~4-fold lower Rb affinity and ~3-fold higher bumetanide affinity than NKCC1; NKCC1 activity is governed primarily by intracellular [Cl-] rather than cell volume; NKCC2 activity responds to volume changes and intracellular [Cl-] in parallel, supporting a model where NKCC2 apical activity is matched to basolateral Cl- exit via [Cl-]i. Stable expression in HEK-293 cells, 86Rb uptake kinetics, chimeric construct analysis, ion substitution experiments The Journal of biological chemistry High 9556622

Source papers

Stage 0 corpus · 100 papers · ranked by NIH iCite citations
Year Title Journal Citations PMID
2014 Contributions of the Na⁺/K⁺-ATPase, NKCC1, and Kir4.1 to hippocampal K⁺ clearance and volume responses. Glia 221 24482245
2003 PASK (proline-alanine-rich STE20-related kinase), a regulatory kinase of the Na-K-Cl cotransporter (NKCC1). The Journal of biological chemistry 220 12740379
2012 Cation-chloride cotransporters NKCC1 and KCC2 as potential targets for novel antiepileptic and antiepileptogenic treatments. Neuropharmacology 213 22705273
1997 Expression of the Na(+)-K(+)-2Cl- cotransporter BSC2 in the nervous system. The American journal of physiology 200 9038823
1999 Mutation of the Na-K-Cl co-transporter gene Slc12a2 results in deafness in mice. Human molecular genetics 137 10401008
2012 SPAK/OSR1 regulate NKCC1 and WNK activity: analysis of WNK isoform interactions and activation by T-loop trans-autophosphorylation. The Biochemical journal 114 22032326
1998 Comparison of Na-K-Cl cotransporters. NKCC1, NKCC2, and the HEK cell Na-L-Cl cotransporter. The Journal of biological chemistry 110 9556622
2010 Physiological relevance of cell-specific distribution patterns of CFTR, NKCC1, NBCe1, and NHE3 along the crypt-villus axis in the intestine. American journal of physiology. Gastrointestinal and liver physiology 108 21030607
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2010 Altered expression of regulators of the cortical chloride transporters NKCC1 and KCC2 in schizophrenia. Archives of general psychiatry 92 20819979
2020 Role of NKCC1 and KCC2 in Epilepsy: From Expression to Function. Frontiers in neurology 86 32010056
2001 A novel method of gene transcript profiling in airway biopsy homogenates reveals increased expression of a Na+-K+-Cl- cotransporter (NKCC1) in asthmatic subjects. Genome research 82 11544191
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2008 Long-term expressional changes of Na+ -K+ -Cl- co-transporter 1 (NKCC1) and K+ -Cl- co-transporter 2 (KCC2) in CA1 region of hippocampus following lithium-pilocarpine induced status epilepticus (PISE). Brain research 77 18550034
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2007 Dynamic and differential regulation of NKCC1 by calcium and cAMP in the native human colonic epithelium. The Journal of physiology 62 17478539
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2012 NKCC1 knockdown decreases neuron production through GABA(A)-regulated neural progenitor proliferation and delays dendrite development. The Journal of neuroscience : the official journal of the Society for Neuroscience 59 23015452
2020 Structure of the human cation-chloride cotransporter NKCC1 determined by single-particle electron cryo-microscopy. Nature communications 57 32081947
2017 NKCC1 Regulates Migration Ability of Glioblastoma Cells by Modulation of Actin Dynamics and Interacting with Cofilin. EBioMedicine 57 28679472
1997 Expression of the bumetanide-sensitive Na-K-Cl cotransporter BSC2 is differentially regulated by fluid mechanical and inflammatory cytokine stimuli in vascular endothelium. The Journal of clinical investigation 56 9185518
2005 Contribution of the basolateral isoform of the Na-K-2Cl- cotransporter (NKCC1/BSC2) to renin secretion. American journal of physiology. Renal physiology 53 16106034
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2009 Nkcc1 (Slc12a2) is required for the regulation of endolymph volume in the otic vesicle and swim bladder volume in the zebrafish larva. Development (Cambridge, England) 47 19633174
2007 Sex differences in the chloride cotransporters, NKCC1 and KCC2, in the developing hypothalamus. Journal of neuroendocrinology 47 17355320
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2017 Astaxanthin protects astrocytes against trauma-induced apoptosis through inhibition of NKCC1 expression via the NF-κB signaling pathway. BMC neuroscience 44 28490320
2022 NLRP3 inflammasome-mediated choroid plexus hypersecretion contributes to hydrocephalus after intraventricular hemorrhage via phosphorylated NKCC1 channels. Journal of neuroinflammation 43 35729645
2014 Cellular iron homeostasis mediated by the Mrs4-Ccc1-Smf3 pathway is essential for mitochondrial function, morphogenesis and virulence in Candida albicans. Biochimica et biophysica acta 43 24368185
2014 Role of the Na ⁺/K ⁺/2Cl⁻ cotransporter NKCC1 in cell cycle progression in human esophageal squamous cell carcinoma. World journal of gastroenterology 43 24944475
2007 Conservation of hearing by simultaneous mutation of Na,K-ATPase and NKCC1. Journal of the Association for Research in Otolaryngology : JARO 41 17674100
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2002 Mouse mammary epithelial cells express the Na-K-Cl cotransporter, NKCC1: characterization, localization, and involvement in ductal development and morphogenesis. Molecular endocrinology (Baltimore, Md.) 40 12040017
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2018 NKCC1 promotes EMT-like process in GBM via RhoA and Rac1 signaling pathways. Journal of cellular physiology 38 30159893
2008 Salt sensitivity of blood pressure in NKCC1-deficient mice. American journal of physiology. Renal physiology 38 18701622
2002 Molecular regulation of Na+-K+-2Cl- cotransporter (NKCC1) and epithelial chloride secretion. World journal of surgery 38 11948363
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2003 Prolonged interferon-gamma exposure decreases ion transport, NKCC1, and Na+-K+-ATPase expression in human intestinal xenografts in vivo. American journal of physiology. Gastrointestinal and liver physiology 37 12958023
2001 Alterations in airway ion transport in NKCC1-deficient mice. American journal of physiology. Cell physiology 37 11443061
2018 Pretreatment with AQP4 and NKCC1 Inhibitors Concurrently Attenuated Spinal Cord Edema and Tissue Damage after Spinal Cord Injury in Rats. Frontiers in physiology 36 29403391
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2013 Direct control of Na(+)-K(+)-2Cl(-)-cotransport protein (NKCC1) expression with aldosterone. American journal of physiology. Cell physiology 35 24173102
2011 Phosphorylation and transport in the Na-K-2Cl cotransporters, NKCC1 and NKCC2A, compared in HEK-293 cells. PloS one 35 21464992
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2018 Activation of TRPV1 channels leads to stimulation of NKCC1 cotransport in the lens. American journal of physiology. Cell physiology 27 30207782
2012 Kinases SPAK and OSR1 are upregulated by estradiol and activate NKCC1 in the developing hypothalamus. The Journal of neuroscience : the official journal of the Society for Neuroscience 27 22238094
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2021 Restoring neuronal chloride homeostasis with anti-NKCC1 gene therapy rescues cognitive deficits in a mouse model of Down syndrome. Molecular therapy : the journal of the American Society of Gene Therapy 26 34058387
2017 The Ubiquitin Ligase Nedd4L Regulates the Na/K/2Cl Co-transporter NKCC1/SLC12A2 in the Colon. The Journal of biological chemistry 26 28087701
2017 Discovery of NKCC1 as a potential therapeutic target to inhibit hepatocellular carcinoma cell growth and metastasis. Oncotarget 26 29029515
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2008 Roles of basolateral solute uptake via NKCC1 and of myosin II in vasopressin-induced cell swelling in inner medullary collecting duct. American journal of physiology. Renal physiology 26 18417545
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2007 Mice lacking NKCC1 have normal olfactory sensitivity. Physiology & behavior 25 17719611
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2022 The role of KCC2 and NKCC1 in spinal cord injury: From physiology to pathology. Frontiers in physiology 18 36589461
2020 Androgenic Modulation of the Chloride Transporter NKCC1 Contributes to Age-dependent Isoflurane Neurotoxicity in Male Rats. Anesthesiology 18 32930727
2017 The Role of Na:K:2Cl Cotransporter 1 (NKCC1/SLC12A2) in Dental Epithelium during Enamel Formation in Mice. Frontiers in physiology 18 29209227
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