| 2001 |
AXOR12/GPR54 (KISS1R) is a G protein-coupled receptor that is activated by peptides derived from the KiSS-1 gene (kisspeptins), including surrogate agonist peptides with a common C-terminal amidated motif; heterologous expression in mammalian cells confirmed ligand-receptor pairing. GPR54 was also shown to be activated by invertebrate FMRFamide-related neuropeptides (RFamide/RWamide family) via the Gαq pathway, with the C-terminal optimal sequence Gly-Leu-Arg-Trp-NH2. |
Heterologous expression in mammalian cells, functional agonist screening, substitution analysis, Northern analysis |
The Journal of biological chemistry / Biochemical and biophysical research communications |
High |
11387329 11414709
|
| 2003 |
Loss-of-function mutations in GPR54 (L148S homozygous; compound heterozygous R331X/X399R) cause autosomal recessive idiopathic hypogonadotropic hypogonadism in humans. In vitro transfection of COS-7 cells with mutant constructs demonstrated significantly decreased inositol phosphate accumulation, establishing that GPR54 signals via Gαq/11-coupled phospholipase C pathway. Gpr54-deficient mice recapitulated isolated hypogonadotropic hypogonadism with normal hypothalamic GnRH levels, placing GPR54 upstream of GnRH secretion (not GnRH synthesis). |
Human genetics (homozygosity mapping, sequencing), in vitro transfection/inositol phosphate assay (COS-7 cells), Gpr54 knockout mouse phenotyping |
The New England journal of medicine |
High |
14573733
|
| 2003 |
Targeted disruption of GPR54 in mice results in developmental abnormalities of male and female genitalia and loss of sexually dimorphic tissue features, confirming that the GPR54/KiSS-1 system is essential for normal reproductive system development. |
Gpr54 knockout mouse generation and phenotypic analysis (histopathology, organ morphology) |
Biochemical and biophysical research communications |
High |
14652023
|
| 2005 |
Activation of GPR54 by kisspeptin-10 in MDA-MB-435S cells promotes cell cycle arrest and apoptosis through a specific transcriptional program; this program requires PLC and PKC activation (upstream), and a subset of genes also requires p42/44 MAPK. The program is distinct from that activated by the bradykinin B2 receptor despite shared Gq/11 coupling, indicating GPR54-specific downstream gene regulation. |
cDNA microarray time-course, pharmacological inhibitors of PLC, PKC, and p42/44 MAPK, apoptosis assays, comparison with B2 receptor |
Biochemical and biophysical research communications |
Medium |
15596153
|
| 2008 |
GPR54 signaling activates multiple intracellular pathways: Gαq/11-coupled PLC activation leading to IP3 accumulation, intracellular Ca2+ mobilization, and PKC activation; additionally ERK1/2 and p38 MAPK activation, PI3K/Akt, and effects on MMP9 expression via NFκB and calcineurin expression. GPR54 can also cross-talk with CXCR4 and GnRH receptor. |
Review synthesizing published functional assays across multiple cell types |
Peptides |
Medium |
18775460
|
| 2008 |
In hippocampal dentate granule cells, GPR54 activation by kisspeptin-10 causes rapid, large increases in excitatory synaptic (AMPA receptor-mediated) response amplitude without changing membrane properties. This effect is postsynaptic, requires G-protein signaling (GDP-β-S-sensitive), intracellular Ca2+ (BAPTA-sensitive), and is abolished by inhibitors of ERK1/2, tyrosine kinase, and CaMKII. |
Electrophysiology (field recordings, mEPSC analysis), pharmacological inhibitors, RT-PCR, hippocampal slice cultures |
Peptides |
Medium |
18765263
|
| 2008 |
The C-terminal cytoplasmic domain of GPR54, containing a proline- and arginine-rich segment with four overlapping SH3-binding motifs, physically associates with the catalytic subunit of protein phosphatase 2A (PP2A-C). GST pull-down experiments confirmed binding to PP2A-C in cell lysates, the complexes retained phosphatase activity, and direct binding to purified recombinant PP2A-C was demonstrated. The proline-arginine rich segment is necessary for this interaction. |
Yeast two-hybrid, GST fusion protein pull-down, phosphatase activity assay, binding to purified recombinant PP2A-C |
Biochemical and biophysical research communications |
High |
18977201
|
| 2009 |
GPR54 signaling is regulated by GRK2 and β-arrestins 1 and 2. GPR54 is expressed at the plasma membrane and intracellularly, with membrane expression regulated by cytoplasmic tail sequences. GPR54 exhibits constitutive activity, undergoes agonist-induced internalization, and associates with GRK2 and β-arrestins through sequences in the second intracellular loop and cytoplasmic tail. GRK2 stimulates GPR54 desensitization; β-arrestin-2 mediates GPR54 activation of ERK1/2. |
Transfection of HEK293 cells and MDA-MB-231 cells (β-arrestin-2-deficient), co-immunoprecipitation, confocal imaging, ERK1/2 phosphorylation assays, receptor internalization assays |
Molecular endocrinology |
High |
19846537
|
| 2011 |
Kisspeptin-10 (Kp-10) via GPR54 stimulates invasion of ERα-negative breast cancer cells (MDA-MB-231, Hs578T) and induces invasive stellate structures in 3D. Kp-10 increases MMP-9 activity. GPR54 directly associates (FRET-confirmed) with EGFR; Kp-10 stimulates EGFR transactivation, and this is increased upon Kp-10 treatment. β-arrestin 2 knockdown inhibits both EGFR transactivation and Kp-10-induced invasion. |
Matrigel invasion assays, 3D invasion assays, MMP-9 activity assay, β-arrestin-2 knockdown, FRET analysis, EGFR phosphorylation assays |
PloS one |
High |
21738726
|
| 2011 |
KISS1R intracellular trafficking: WT KISS1R is degraded by proteasomes rather than lysosomes (proteasome inhibitor increased protein 24-fold; lysosome inhibitor had no effect). Upon kisspeptin stimulation, both WT and Arg386Pro KISS1R are internalized and recycled back to the membrane rather than degraded. The Arg386Pro gain-of-function mutation does not affect trafficking rate but decreases receptor degradation, resulting in net accumulation of recycled receptor at the plasma membrane, prolonging kisspeptin responsiveness. |
Confocal imaging with membrane and lysosome markers, proteasome and lysosome inhibitors, receptor internalization and recycling assays in transfected cells |
Endocrinology |
High |
21285314
|
| 2011 |
Kiss1r haploinsufficiency in MMTV-PyMT mice attenuates breast cancer initiation, growth, latency, multiplicity, and lung metastasis. Kisspeptin-10 stimulation of Kiss1r activates RhoA through the Gαq-p63RhoGEF signaling pathway, and anchorage-independent growth is dose-dependently regulated by RhoA downstream of Kiss1r. siRNA knockdown of KISS1R or RhoA inactivation reduces Ras-induced anchorage-independent growth. |
Kiss1r heterozygous knockout in MMTV-PyMT mouse model, primary tumor cell isolation, in vitro tumorigenic assays, in vivo tumor growth in immunocompromised mice, RhoA activation assays, siRNA knockdown |
Cancer research |
High |
21852382
|
| 2012 |
Sustained KISS1R signaling requires extracellular Ca2+. In single-cell analyses, chronic Kp-10 stimulation triggers prolonged activation of PLC, PKC, and Ca2+ mobilization in HEK293, GT1-7 GnRH neuronal, and CHO cells. Intracellular Ca2+ from stores is sufficient for acute PKC activation but insufficient for sustained signaling; extracellular Ca2+ influx is absolutely required for prolonged KISS1R signaling. |
Single-cell Ca2+ imaging, PKC activity assays, pharmacological Ca2+ chelation/channel blockade in multiple cell lines |
Endocrinology |
High |
23070548
|
| 2013 |
The key cellular site of kisspeptin-Gpr54 signaling for fertility is the GnRH neuron. GnRH neuron-specific deletion of Gpr54 causes infertility, failure of puberty, reduced gonadal size, reduced FSH, and GnRH neurons unresponsive to kisspeptin. BAC transgenic rescue of Gpr54 expression specifically in GnRH neurons of global Gpr54-/- mice restores normal puberty, estrous cyclicity, fecundity, and kisspeptin responsiveness of GnRH neurons. |
Conditional knockout (GnRH neuron-specific Gpr54 deletion), BAC transgenesis for cell-specific knockin rescue, in vivo kisspeptin responsiveness testing, reproductive phenotyping |
Nature communications |
High |
24051579
|
| 2013 |
KISS1R induces invasiveness in ERα-negative breast cancer cells via EGFR transactivation. ERα expression negatively regulates KISS1R-dependent migration, invasion, and EGFR transactivation by downregulating KISS1R expression. IQGAP1, an actin cytoskeletal scaffolding protein, was identified as a novel binding partner of KISS1R by co-immunoprecipitation, and KISS1R regulates EGFR transactivation in a KISS1R-IQGAP1-dependent manner. |
Co-immunoprecipitation (KISS1R-IQGAP1 interaction), invasion assays, EGFR transactivation assays, ERα re-expression experiments, IQGAP1 knockdown |
Endocrinology |
Medium |
23525242
|
| 2014 |
KISS1R signals independently of Gαq/11 via β-arrestin to trigger LH (GnRH) secretion. In mice lacking β-arrestin-1 or β-arrestin-2, kisspeptin-dependent LH secretion was significantly diminished. The disease-associated Gαq/11-uncoupled L148S mutant retained the ability to trigger Kp-dependent ERK1/2 phosphorylation via a β-arrestin-dependent mechanism (demonstrated using MEFs lacking both β-arrestins). |
β-arrestin-1 and -2 knockout mice (LH secretion assay), HEK293 cell transfection with L148S mutant, MEF cells lacking β-arrestins, ERK1/2 phosphorylation assays |
Endocrinology |
High |
25147978
|
| 2014 |
KiSS1/GPR54 signaling inhibits breast cancer cell migration and EMT through protein kinase D1 (PKD1). Kisspeptin stimulation elevates phosphorylated PKD1 in a PKC-dependent manner. GPR54 knockdown increases migration/invasion and blocks kisspeptin-induced PKD1 phosphorylation. PKD1 phosphorylation decreases expression of the EMT transcription factor Slug and increases E-cadherin expression. |
siRNA knockdown of GPR54 and PKD1, PKD1 phosphorylation assays, migration/invasion assays, colony formation assays, Slug and E-cadherin expression analysis |
Current molecular medicine |
Medium |
24894166
|
| 2014 |
Loss of Kiss1r in oocytes causes impaired response to gonadotropins: oocytes lacking KISS1R fail to upregulate NTRK2 full-length receptor (NTRK2.FL) in response to the preovulatory LH surge. In a cell line co-expressing NTRK2.T1 and KISS1R, BDNF stimulation only activates NTRK2 expression if kisspeptin is present, and NTRK2.FL induction by gonadotropins fails in the absence of KISS1R in intact mice. |
Oocyte-specific Ntrk2 and Kiss1r conditional knockouts, in vitro BDNF/kisspeptin co-stimulation, Western blotting, RT-PCR, PI3K-AKT signaling assays |
Endocrinology |
Medium |
24877631
|
| 2015 |
RF9 acts as a direct KISS1R agonist (not allosteric modulator). In CHO cells stably transfected with KISS1R, RF9 binds specifically to KISS1R (Kd ~1.6×10-5 M), stimulates intracellular Ca2+ increase and inositol phosphate accumulation (KISS1R-dependent), and stimulates ERK phosphorylation. In vivo, RF9-stimulated LH increase persists in Npffr1-/- mice but is markedly reduced in Kiss1r-/- mice and is rescued by GnRH neuron-specific Kiss1r re-expression. |
Radioligand binding assay, IP accumulation assay, Ca2+ assay, ERK phosphorylation, Npffr1-/-, Kiss1r-/-, and GnRH neuron-specific rescue mice |
Endocrinology |
High |
26418326
|
| 2015 |
KISS1R signaling induces invadopodia formation in triple-negative breast cancer cells via a β-arrestin2- and ERK1/2-dependent mechanism, independent of Src. KISS1R activates cortactin, cofilin, and MT1-MMP (key invadopodia proteins). Depletion of KISS1R reduces mesenchymal phenotype and invasiveness. |
KISS1R knockdown/depletion, β-arrestin2 knockdown, invadopodia formation assays, cortactin/cofilin/MT1-MMP activity assays, ERK1/2 inhibition |
Cellular signalling |
Medium |
26721186
|
| 2018 |
Kisspeptin/GPR54 signaling restricts antiviral innate immune responses by recruiting calcineurin and increasing its phosphatase activity to dephosphorylate and inactivate TBK1 in a Ca2+-dependent manner, thereby suppressing type I interferon production. Gpr54-deficient cells and mice showed enhanced IFN-I production and restricted viral replication. |
Gpr54 knockout cells and mice, calcineurin phosphatase activity assays, TBK1 dephosphorylation assays, IFN-I production measurement, viral replication assays |
Science advances |
High |
30101190
|
| 2018 |
KP-10/GPR54 signaling in macrophages binds PP2A-C and suppresses LPS-induced NF-κB and MAPK signaling, reducing inflammatory cytokine production. In vivo, KP-10 ameliorated collagen-induced arthritis in mice, while Gpr54-/- increased CIA severity. The mechanism involves GPR54 recruiting PP2A catalytic subunit to dephosphorylate/inactivate NF-κB and MAPK pathway components. |
Western blotting, immunofluorescence, BMDM KO cells, CIA mouse model, in vitro LPS stimulation, cytokine measurement |
Pharmacological research |
Medium |
33609696
|
| 2018 |
KP-10 via GPR54 stimulates osteoblast differentiation by upregulating BMP2 expression through NFATc4-mediated transcription, activating Smad1/5/9 phosphorylation. BMP2 protein secreted acts in an autocrine manner. This effect is GPR54-dependent: KP-10 did not induce BMP2 or Runx2 expression in GPR54-/- cells, though conditioned medium from KP-10-treated cells could rescue Dlx5/Runx2 in GPR54-/- cells. |
KP-10 treatment of C3H10T1/2 cells and GPR54-/- cells, BMP2-luciferase reporter, Smad1/5/9 phosphorylation, conditioned medium experiments, osteogenic gene expression |
Scientific reports |
Medium |
29391507
|
| 2018 |
GPR54 promotes adipocyte differentiation and fat accumulation. In 3T3-L1 cells, Kp-10 accelerates adipocyte differentiation and promotes triglyceride synthesis. Primary MSCs from Gpr54-/- mice are less likely to differentiate into adipocytes. Gpr54-/- mice on high-fat diet show reduced adiposity, smaller adipocyte size, lower triglycerides, and reduced PPARγ expression. ERK phosphorylation is decreased in Gpr54-/- mice, suggesting GPR54 promotes lipid synthesis via MAP kinase pathway. |
Gpr54 knockout mice, 3T3-L1 differentiation assays, primary MSC differentiation, lipid staining, triglyceride measurement, ERK phosphorylation, gene expression analysis |
Frontiers in physiology |
Medium |
29593567
|
| 2022 |
GPR54 in T cells mediates kisspeptin-induced T cell dysfunction during tumor immune evasion via ERK5-mediated NR4A1 activation. Kisspeptin-10 impairs T cell function; Gpr54 knockout in T cells inhibits lung tumor progression by suppressing T cell dysfunction/exhaustion. CRISPR/Cas9 depletion of GPR54 or ERK5 in CAR-T cells enhances antitumor responses and eliminates T cell exhaustion. |
T cell-specific Gpr54 knockout, kisspeptin-10 treatment, ERK5 inhibitor (XMD8-92), CRISPR/Cas9 knockout of GPR54/ERK5 in CAR-T cells, in vivo tumor models, T cell functional assays |
Advanced science |
Medium |
35224894
|
| 2007 |
GPR54 signaling is required for proper male sexual differentiation of the brain. GPR54 KO males display female-like numbers of tyrosine hydroxylase-immunoreactive neurons and Kiss1 mRNA-containing neurons in the AVPV, and fewer motoneurons in the spino-bulbocavernosus nucleus, indicating that perinatal kisspeptin-GPR54 signaling regulates androgen-dependent brain masculinization during critical developmental windows. Copulatory behavior, however, is intact with appropriate adult hormone replacement. |
GPR54 knockout mouse phenotyping, immunohistochemistry for TH neurons, in situ hybridization for Kiss1 mRNA, motoneuron counting, sexual behavior testing with gonadal hormone replacement |
The Journal of neuroscience |
High |
17699664
|
| 2010 |
A novel loss-of-function mutation (p.F272S) in GPR54 causes almost complete inhibition of kisspeptin-induced GPR54 signaling and dramatically decreases mutated receptor expression at the cell surface, establishing that proper cell surface expression of GPR54 is required for functional kisspeptin signaling. |
GPR54 sequencing, in vitro transfection and functional signaling assay, cell surface expression analysis |
The Journal of clinical endocrinology and metabolism |
Medium |
21193544
|
| 2013 |
A novel KISS1R mutation (p.Tyr313His) in the seventh transmembrane domain impairs MAP kinase signaling and intracellular calcium release, establishing the functional importance of Tyr313 in KISS1R signal transduction. GnRH administration to a patient with KISS1R compound heterozygous mutations restored pulsatile LH secretion, confirming the defect is hypothalamic in origin. |
KISS1R gene sequencing, in vitro functional characterization (MAPK assay, intracellular Ca2+ measurement), pulsatile GnRH administration in patients |
PloS one |
Medium |
23349759
|
| 2017 |
In the arcuate nucleus, approximately 63% of Kiss1r-expressing neurons are POMC neurons, and approximately 15% are tuberoinfundibular dopamine (TIDA) neurons. NPY and kisspeptin neurons in the ARN do not express Kiss1r. This neurochemical characterization establishes direct kisspeptin targets beyond GnRH neurons in the hypothalamus. |
In situ hybridization combined with immunofluorescence in female rat hypothalamus |
Journal of neuroendocrinology |
Medium |
27981646
|
| 2023 |
GPR54 receptors are expressed and localized in human pancreatic islets, visualized using novel fluorogenic kisspeptin-based probes (Trp-BODIPY PLUS) that exhibit turn-on fluorescence upon target binding; confirming GPR54 receptor presence and subcellular localization in intact pancreatic tissue. |
Fluorescence imaging with novel BODIPY-based kisspeptin fluorogenic probes in human cells and whole mouse pancreatic islets |
Angewandte Chemie (International ed. in English) |
Low |
36917014
|