Affinage

CLIC5

Chloride intracellular channel protein 5 · UniProt Q9NZA1

Length
410 aa
Mass
46.5 kDa
Annotated
2026-06-09
24 papers in source corpus 14 papers cited in narrative 14 extracted findings
Cross-family judge vs UniProt: Affinage preferred faithfulness: 7/7 claims corpus-supported (100%)

Mechanistic narrative

Synthesis pass · prose summary of the discoveries below

CLIC5 is a chloride intracellular channel protein that links the plasma membrane to the cortical actin cytoskeleton at actin-rich membrane specializations, where it stabilizes membrane–actin junctions critical for the integrity of microvilli, stereocilia, and podocyte foot processes (PMID:10793131, PMID:17021174, PMID:20664558). It was first isolated from placental microvilli as part of a detergent-insoluble cytoskeletal complex containing actin, ezrin, alpha-actinin, gelsolin, and IQGAP1 (PMID:10793131), and it constitutively associates with ERM-family proteins (radixin, ezrin) and podocalyxin in both stereocilia and podocytes (PMID:17021174, PMID:20664558). Purified recombinant CLIC5 inserts into planar lipid bilayers to form multiconductance channels permeable to Na+, K+, and Cl-, whose activity is strongly and reversibly inhibited by F-actin in the absence of any other protein, directly coupling channel function to cytoskeletal state (PMID:18028448). At the stereociliary base, CLIC5 forms a complex with radixin, taperin, and myosin VI, and its loss causes progressive stereocilia fusion, mislocalization of partner proteins, hair cell degeneration, deafness, and vestibular dysfunction (PMID:17021174, PMID:24285636); the functionally important GRXCR2–CLIC5 interaction at this site is also required for normal hearing (PMID:34026762). In podocytes, CLIC5 loss reduces the ERM complex and podocalyxin and produces foot process abnormalities and proteinuria (PMID:20664558). CLIC5 also localizes to cilia/centrosomes and supports ciliogenesis and cilia-dependent signaling, with deficiency reducing ERM phosphorylation (PMID:29425878, PMID:37848494). Beyond its cytoskeletal scaffolding role, CLIC5 promotes myogenic differentiation and skeletal muscle regeneration by interacting with biglycan to activate canonical Wnt/β-catenin signaling (PMID:39999205).

Mechanistic history

Synthesis pass · year-by-year structured walk · 14 steps
  1. 2000 Medium

    Established CLIC5 as a cytoskeleton-associated component of actin-rich membrane specializations rather than a free cytosolic protein, distinguishing it from other CLIC family members.

    Evidence Biochemical fractionation and co-isolation from placental microvilli with immunofluorescence localization

    PMID:10793131

    Open questions at the time
    • Did not establish direct binary interactions within the complex
    • No channel function demonstrated
    • Functional consequence of complex assembly unknown
  2. 2006 High

    Linked CLIC5 loss-of-function to a defined cellular and organismal phenotype, showing it is required to maintain stereocilia and hearing and associates with radixin.

    Evidence Spontaneous jitterbug mouse mutant with immunohistochemistry, mass spectrometry, and immunolocalization

    PMID:17021174

    Open questions at the time
    • Direct CLIC5–radixin binding not biochemically isolated
    • Whether channel activity is required for the phenotype untested
  3. 2007 High

    Demonstrated that CLIC5 is an intrinsic membrane-inserting ion channel whose activity is directly gated by F-actin, providing a molecular basis for coupling membrane conductance to cytoskeletal state.

    Evidence Planar lipid bilayer reconstitution with purified recombinant protein and cytochalasin treatment

    PMID:18028448

    Open questions at the time
    • Physiological ion selectivity in vivo unresolved
    • Structural transition for membrane insertion not defined
    • Link between channel activity and tissue phenotypes not established
  4. 2010 High

    Extended CLIC5's membrane–cytoskeleton scaffolding role to podocytes, showing it stabilizes the ERM complex and podocalyxin to maintain foot process architecture and the filtration barrier.

    Evidence Slit diaphragm proteomics, co-immunoprecipitation, and CLIC5-knockout mouse with proteinuria and EM phenotype

    PMID:20664558

    Open questions at the time
    • Mechanism by which CLIC5 stabilizes ERM/podocalyxin unresolved
    • Role of channel activity vs. scaffolding not separated
  5. 2013 High

    Placed CLIC5 within a defined radixin–taperin–myosin VI complex and showed genetic epistasis with MYO6, establishing it as part of a membrane-actin linkage machine at the stereociliary base.

    Evidence Co-immunoprecipitation, confocal/scanning EM, and jbg and MYO6 mutant mouse models

    PMID:24285636

    Open questions at the time
    • Order of complex assembly and direct binding interfaces not mapped
    • Whether channel function contributes to linkage stability untested
  6. 2015 Medium

    Suggested CLIC5–ezrin–podocalyxin complexes promote cell migration and invasion in a cancer context, extending the scaffolding role to motility.

    Evidence shRNA knockdown with migration/invasion assays in Huh7 hepatocellular carcinoma cells

    PMID:26135398

    Open questions at the time
    • No mechanistic dissection of the complex
    • Off-target effects of shRNA not excluded
    • Generalizability beyond one cell line unknown
  7. 2016 Medium

    Identified CLIC5 as a direct ETV6 transcriptional target and linked its channel activity to lysosomal cell death and oxidative stress resistance.

    Evidence ChIP, transcriptome analysis, overexpression apoptosis assays, and colocalization with transferrin receptor

    PMID:27540136

    Open questions at the time
    • Transferrin receptor link is correlative
    • Mechanism connecting channel activity to lysosomal death undefined
  8. 2018 Medium

    Showed CLIC5 expression in the lens is controlled by KLPH/lctl and that CLIC5 localizes to cilia/centrosomes, implicating it in lens fiber organization.

    Evidence RNA-seq and immunofluorescence in KLPH-knockout and jitterbug mouse models

    PMID:29425878

    Open questions at the time
    • Function of ciliary/centrosomal CLIC5 in lens not mechanistically defined
    • Whether lens phenotype reflects channel or scaffolding role unknown
  9. 2021 Medium

    Demonstrated that a specific GRXCR2–CLIC5 interaction interface is functionally required for hearing independent of gross stereocilia morphogenesis.

    Evidence Co-immunoprecipitation plus CRISPR/Cas9 in-frame deletion of the interaction domain with auditory testing

    PMID:34026762

    Open questions at the time
    • Molecular consequence of losing the interaction at the stereociliary base unresolved
    • Whether GRXCR2 recruits or stabilizes CLIC5 not determined
  10. 2023 Medium

    Connected CLIC5 to ciliogenesis and ERM phosphorylation in vivo, linking ciliary CLIC5 to cilia-dependent Wnt signaling and the glomerular filtration barrier.

    Evidence Morpholino knockdown of CLIC5a/CLIC5b isoforms in zebrafish with phenotypic and immunostaining analysis

    PMID:37848494

    Open questions at the time
    • Morpholino off-target effects not fully excluded
    • Direct mechanism connecting CLIC5 to ERM phosphorylation undefined
    • Isoform-specific functions only partially separated
  11. 2024 Medium

    Defined a signaling role for CLIC5 in muscle, showing it interacts with biglycan to activate canonical Wnt/β-catenin signaling driving satellite cell differentiation and regeneration.

    Evidence Muscle-specific knockout and overexpression mice, CLIC5–BGN co-immunoprecipitation, and Wnt/β-catenin pathway assays

    PMID:39999205

    Open questions at the time
    • How CLIC5–BGN binding activates Wnt signaling mechanistically unresolved
    • Whether channel activity contributes untested
  12. 2010 Low

    Provided early evidence that CLIC5 expression promotes myogenic differentiation while suppressing proliferation.

    Evidence Constitutive overexpression in C2C12 myoblasts with cell cycle analysis and myogenic marker immunoblots

    PMID:20055760

    Open questions at the time
    • Single overexpression experiment with no pathway placement
    • Endogenous loss-of-function not tested
  13. 2022 Low

    Identified curcumin as a direct biophysical interactant of CLIC5, a candidate chemical probe.

    Evidence Thermal shift assay (differential scanning fluorimetry) screening with purified recombinant CLIC5

    PMID:37584386

    Open questions at the time
    • No functional validation of the interaction
    • Binding site and biological relevance unknown
  14. 2026 Low

    Suggested a mitochondrial localization and TSPO proximity for CLIC5, raising the possibility it underlies a mitochondrial chloride conductance.

    Evidence FRET acceptor photobleaching in immunolabeled cardiomyoblasts

    PMID:41764818

    Open questions at the time
    • Single FRET measurement without functional validation
    • Identity as the centum-pS mitochondrial channel not established
    • Functional consequence of TSPO proximity unknown

Open questions

Synthesis pass · forward-looking unresolved questions
  • It remains unresolved how CLIC5's reconstituted ion channel activity relates mechanistically to its scaffolding functions in vivo, and whether channel conductance is required for any of the documented tissue phenotypes.
  • No structure of the membrane-inserted channel
  • Channel-dead mutant phenotypes not reported
  • Relationship between cytosolic scaffold and inserted channel states undefined

Mechanism profile

Synthesis pass · controlled-vocabulary classification · explore literature graph →
Molecular activity
GO:0008092 cytoskeletal protein binding 2 GO:0060090 molecular adaptor activity 2 GO:0005215 transporter activity 1
Localization
GO:0005886 plasma membrane 3 GO:0005856 cytoskeleton 2 GO:0005929 cilium 2 GO:0005815 microtubule organizing center 1
Pathway
R-HSA-1266738 Developmental Biology 1 R-HSA-162582 Signal Transduction 1
Partners
BGNEZRGRXCR2IQGAP1MYO6PODXLRDXTPRN
Complex memberships
CLIC5–radixin–taperin–myosin VI stereociliary complexERM–podocalyxin podocyte complexactin/ezrin/alpha-actinin/gelsolin/IQGAP1 microvillar complex

Evidence

Reading pass · 14 per-paper findings extracted from the source corpus
Year Finding Method Journal Conf PMIDs
2000 CLIC5 was isolated from placental microvilli as a component of a multimeric complex containing actin, ezrin, alpha-actinin, gelsolin, and IQGAP1; it associates with the detergent-insoluble cytoskeletal fraction of microvilli and localizes to the apical region of trophoblasts, distinguishing it from CLIC1 and CLIC4. Biochemical fractionation (detergent-insoluble fraction), co-isolation/pulldown, immunoblot, indirect immunofluorescence microscopy Molecular biology of the cell Medium 10793131
2006 CLIC5 is expressed at high levels in the basal region of hair cell stereocilia (in approximate 1:1 molar ratio with radixin), and loss-of-function (jitterbug mutation causing premature stop codon) results in dysmorphic stereocilia, progressive hair cell degeneration, impaired hearing, and vestibular dysfunction; radixin immunostaining was reduced in hair bundles of mutant mice, suggesting CLIC5 associates with radixin to form or stabilize connections between the plasma membrane and the actin core. Spontaneous mouse mutant (jbg, 97 bp deletion/frameshift), immunohistochemistry, mass spectrometry, immunoblot, immunofluorescence The Journal of neuroscience High 17021174
2007 Purified recombinant CLIC5 incorporated into planar lipid bilayers forms multiconductance ion channels that are almost equally permeable to Na+, K+, and Cl-; CLIC5 channel activity is strongly and reversibly inhibited by cytosolic F-actin in the absence of any other protein, an effect reversible by cytochalasin-mediated F-actin disruption. Planar lipid bilayer reconstitution with purified recombinant protein; cytochalasin treatment The FEBS journal High 18028448
2010 CLIC5 is enriched in podocyte foot processes, colocalizes and associates with the ezrin/radixin/moesin (ERM) complex and podocalyxin; CLIC5-knockout mice display decreased foot process length, widespread foot process abnormalities, proteinuria, and significantly decreased ERM complex and podocalyxin in podocytes. Proteomic purification of slit diaphragm fractions, co-immunoprecipitation, immunofluorescence, CLIC5 knockout mouse model with phenotypic readout (proteinuria, electron microscopy) Kidney international High 20664558
2013 CLIC5 forms a molecular complex with radixin (RDX), taperin (TPRN), and myosin VI (MYO6) at the base of stereocilia; loss of CLIC5 (jitterbug mice) causes progressive stereocilia fusion from postnatal day 10 and mislocalization of RDX, PTPRQ, and TPRN; CLIC5 and RDX also fail to localize normally in MYO6-mutant mice, placing CLIC5 in a complex that stabilizes membrane-actin linkages at the stereociliary base. Biochemical interaction assays (co-immunoprecipitation), confocal and scanning electron microscopy, mouse genetic models (jbg and MYO6 mutants), immunofluorescence Cytoskeleton (Hoboken, N.J.) High 24285636
2015 CLIC5 forms a complex with ezrin and podocalyxin in hepatocellular carcinoma cells; shRNA-mediated knockdown of CLIC5 in Huh7 cells decreases migration and invasion. shRNA knockdown, migration/invasion assays, Western blot, immunofluorescence PloS one Medium 26135398
2016 CLIC5 is a direct transcriptional target of ETV6 (identified by ChIP and transcriptome analysis); overexpression of CLIC5 increases resistance to hydrogen peroxide-induced apoptosis; CLIC5 ion channel activity modulates lysosomal-mediated cell death, possibly by affecting transferrin receptor function, with which CLIC5 colocalizes intracellularly. Chromatin immunoprecipitation (ChIP), whole transcriptome analysis, overexpression cell lines, apoptosis assays, colocalization by immunofluorescence Haematologica Medium 27540136
2018 KLPH/lctl is required for lens-specific expression of CLIC5; in KLPH knockout mice, CLIC5 transcripts are completely absent in the lens, and CLIC5 (detected by immunofluorescence) localizes to cilia/centrosomes of lens epithelial cells; jitterbug (Clic5-null) mice also exhibit defective lens sutures, implicating CLIC5 in lens fiber cell extension and organization. RNA-seq (knockout vs. wildtype), immunofluorescence localization, genetic mouse models (KLPH KO and jitterbug) Experimental eye research Medium 29425878
2021 GRXCR2 interacts with CLIC5 at the base of stereocilia; deletion of the 60 amino acid N-terminal region of GRXCR2 required for CLIC5 interaction (by CRISPR/Cas9) causes moderate-to-severe hearing loss despite minimal effects on stereocilia morphogenesis, demonstrating that the GRXCR2–CLIC5 interaction is functionally important for hearing. Co-immunoprecipitation/interaction assay, CRISPR/Cas9 in-frame deletion, auditory function testing, immunolocalization Frontiers in cell and developmental biology Medium 34026762
2023 In zebrafish, CLIC5b isoform localizes to cilia and its knockdown causes defective ciliogenesis with ciliopathy-associated phenotypes (body curvature, otolith defects, altered left-right asymmetry, hydrocephalus, pronephric cysts) and dysregulation of cilia-dependent Wnt signaling; CLIC5a knockdown causes glomerular filtration barrier leakiness; mechanistically, Clic5 deficiency reduces phosphorylation of ERM (Ezrin/Radixin/Moesin) proteins in pronephric tubules. Morpholino/knockdown in zebrafish, whole-mount in situ hybridization, immunostaining, phenotypic analysis Scientific reports Medium 37848494
2024 CLIC5 promotes myogenic differentiation and skeletal muscle regeneration by interacting with biglycan (BGN) to activate the canonical Wnt/β-catenin signaling pathway; CLIC5 deletion reduces satellite cell number and differentiation, impairs Pax7 expression, and reduces BGN-mediated Wnt/β-catenin signaling, while CLIC5 overexpression enhances muscle regeneration. Muscle-specific CLIC5 knockout mice, overexpression in vivo and in vitro, co-immunoprecipitation (CLIC5-BGN interaction), Wnt/β-catenin pathway assays, satellite cell isolation Science advances Medium 39999205
2010 Constitutive overexpression of CLIC5 in C2C12 myoblasts reduces cell proliferation (G2/M to G0/G1 shift) and increases myotube size and number with upregulation of myosin heavy chain, myogenin, and desmin; CLIC5 protein expression increases during differentiation induced by medium switch. Overexpression in C2C12 cells, cell cycle analysis, immunoblot for myogenic markers Cell biology international Low 20055760
2022 Using thermal shift assay screening of ~500 natural compounds, curcumin was identified as a specific interactant of purified recombinant CLIC5, as evidenced by dose-dependent effects on CLIC5 thermal stability. Differential scanning fluorimetry (thermal shift assay) with purified recombinant CLIC5 The Israel Medical Association journal : IMAJ Low 37584386
2026 CLIC5 is localized to the inner mitochondrial membrane in cardiomyoblasts and shows spatial proximity to TSPO (translocator protein) as measured by FRET (24% efficiency, comparable to positive control at 28%), suggesting TSPO may modulate CLIC5 (candidate for the centum-pS mitochondrial chloride channel) activity. FRET (acceptor photobleaching) in immunolabeled cardiomyoblasts Biochemical and biophysical research communications Low 41764818

Source papers

Stage 0 corpus · 24 papers · ranked by NIH iCite citations
Year Title Journal Citations PMID
2000 Identification of a novel member of the chloride intracellular channel gene family (CLIC5) that associates with the actin cytoskeleton of placental microvilli. Molecular biology of the cell 141 10793131
2006 The chloride intracellular channel protein CLIC5 is expressed at high levels in hair cell stereocilia and is essential for normal inner ear function. The Journal of neuroscience : the official journal of the Society for Neuroscience 109 17021174
2007 Functional reconstitution of mammalian 'chloride intracellular channels' CLIC1, CLIC4 and CLIC5 reveals differential regulation by cytoskeletal actin. The FEBS journal 93 18028448
2013 CLIC5 stabilizes membrane-actin filament linkages at the base of hair cell stereocilia in a molecular complex with radixin, taperin, and myosin VI. Cytoskeleton (Hoboken, N.J.) 64 24285636
2010 Proteomic analysis of the slit diaphragm complex: CLIC5 is a protein critical for podocyte morphology and function. Kidney international 56 20664558
2014 Progressive hearing loss and vestibular dysfunction caused by a homozygous nonsense mutation in CLIC5. European journal of human genetics : EJHG 50 24781754
2015 Co-Expression of Ezrin-CLIC5-Podocalyxin Is Associated with Migration and Invasiveness in Hepatocellular Carcinoma. PloS one 43 26135398
2016 CLIC5: a novel ETV6 target gene in childhood acute lymphoblastic leukemia. Haematologica 23 27540136
2018 The klotho-related protein KLPH (lctl) has preferred expression in lens and is essential for expression of clic5 and normal lens suture formation. Experimental eye research 21 29425878
2024 CLIC5 promotes myoblast differentiation and skeletal muscle regeneration via the BGN-mediated canonical Wnt/β-catenin signaling pathway. Science advances 19 39999205
2010 The CLIC5 (chloride intracellular channel 5) involved in C2C12 myoblasts proliferation and differentiation. Cell biology international 18 20055760
2020 Bi-Allelic Novel Variants in CLIC5 Identified in a Cameroonian Multiplex Family with Non-Syndromic Hearing Impairment. Genes 17 33114113
2021 N-Terminus of GRXCR2 Interacts With CLIC5 and Is Essential for Auditory Perception. Frontiers in cell and developmental biology 11 34026762
2023 A novel role for the chloride intracellular channel protein Clic5 in ciliary function. Scientific reports 9 37848494
2002 Identification and mutational analysis of candidate genes for juvenile myoclonic epilepsy on 6p11-p12: LRRC1, GCLC, KIAA0057 and CLIC5. Epilepsy research 9 12200217
2024 Lnc-Clic5 as a sponge for miR-212-5p to inhibit cow barn PM2.5-induced apoptosis in rat alveolar macrophages. Toxicology 8 38583737
2025 AQP1/4, CLIC5 Dysregulation and lipid metabolism alterations in lung cancer. BMB reports 3 40962327
2025 AAV gene therapy rescues hearing and balance in a model of CLIC5 deafness. EMBO molecular medicine 2 40859056
2023 EPS8 variant causes deafness, autosomal recessive 102 (DFNB102) and literature review. Human genome variation 1 36635257
2026 Translocator protein in touch with mitochondrial chloride intracellular channel CLIC5. Biochemical and biophysical research communications 0 41764818
2026 Exclusion of CLIC5 as a Candidate Gene and Identification of NEFM as a Possible Novel Gene Correlated With Autosomal Recessive Pure Cerebellar Ataxia in a Highly Consanguineous Family. Molecular genetics & genomic medicine 0 41913087
2026 Human CLIC5 as a Recurrent Hotspot of HPV 16 Integration in Cervical Cancer. Journal of medical virology 0 41923498
2025 The c.644 G > A p.(Trp215*) founder variant in the CLIC5 gene causes progressive autosomal recessive deafness 103 (DFNB103) in Eastern Siberia. Journal of human genetics 0 40957967
2022 High-throughput analysis of CLIC5 interactants using a thermal-stability assay. The Israel Medical Association journal : IMAJ 0 37584386

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