{"gene":"PLCL2","run_date":"2026-04-28T19:45:44","timeline":{"discoveries":[{"year":1999,"finding":"PLCL2 (PLC-L2) was identified as a novel PLC-like protein that lacks PLC catalytic activity due to replacement of two essential residues (His356→Thr and Tyr552→Phe in the X and Y domains). Its PH domain binds strongly to PI(4,5)P2 and Ins(1,4,5)P3, and moderately to PI(4)P and PI(3,4,5)P3. PLCL2 localizes predominantly to perinuclear areas including the endoplasmic reticulum in myoblast, myotube, and COS7 cells, with the PH domain sufficient for this localization.","method":"Site-directed mutagenesis analysis of catalytic residues; lipid-binding assays; GFP-fusion localization in C2C12 and COS7 cells; subcellular fractionation","journal":"Biochemical and biophysical research communications","confidence":"High","confidence_rationale":"Tier 1 — in vitro lipid binding assays, mutagenesis of active-site residues, direct localization with functional domain dissection","pmids":["10581172"],"is_preprint":false},{"year":2003,"finding":"PLCL2 functions as a negative regulator of B-cell receptor (BCR) signaling. Genetic knockout of PLCL2 in mice causes hyperproliferation of mature B cells in response to BCR cross-linking, enhanced calcium influx, increased NFATc nuclear accumulation, elevated ERK activity, and a stronger T-cell-independent antigen response, without affecting B2 cell development.","method":"PLCL2 knockout mouse model; B cell proliferation assays; calcium flux measurements; NFATc nuclear localization assays; ERK kinase activity assays; antigen response assays","journal":"Molecular and cellular biology","confidence":"High","confidence_rationale":"Tier 2 — clean genetic KO with multiple orthogonal functional readouts (Ca2+ flux, transcription factor localization, kinase activity, immune response)","pmids":["14517301"],"is_preprint":false},{"year":2009,"finding":"PLCL2 (PRIP-2) and its paralog PLCL1 (PRIP-1) together regulate gonadotropin secretion in females. Double-knockout mice show elevated serum LH and FSH levels and increased LH secretion from explanted anterior pituitary glands, resulting in impaired female reproductive function (smaller uterus, altered estrous cycles, reduced litter size).","method":"PLCL1/PLCL2 double-knockout mouse model; serum hormone measurements; explant culture of anterior pituitary glands; estrous cycle monitoring","journal":"Biology of reproduction","confidence":"Medium","confidence_rationale":"Tier 2 — double-KO mouse with defined endocrine phenotype, but PLCL1 and PLCL2 are not genetically separated in this study","pmids":["19553601"],"is_preprint":false},{"year":2021,"finding":"Progesterone receptor isoform B (PGR-B) suppresses uterine contractility through a pathway that increases PLCL2 expression while reducing Oxtr and Trpc3 expression. Both PLCL2 and its paralog PLCL1 can attenuate uterine smooth muscle cell contraction when activated by CRISPRa, defining PLCL2 as a downstream effector of PGR-B-mediated myometrial relaxation.","method":"Transgenic mouse models overexpressing PGR-A or PGR-B; uterine RNA sequencing; ex vivo and in vivo contractility assays; CRISPRa-based gain-of-function in uterine cells","journal":"Proceedings of the National Academy of Sciences of the United States of America","confidence":"High","confidence_rationale":"Tier 2 — multiple orthogonal methods (transgenic models, RNA-seq, functional contractility assays, CRISPRa) establishing pathway position and functional consequence","pmids":["33707208"],"is_preprint":false},{"year":2022,"finding":"PLCL2 (PRIP-2) acts as a positive regulator of insulin signaling in adipocytes by interacting with the insulin receptor (IR) and modulating IR internalization. In PLCL2/PLCL1 double-knockout adipocytes, insulin-stimulated phosphorylation of IR, IRS-1, and Akt is impaired, glucose uptake is reduced, and cell-surface IR is decreased. Co-immunoprecipitation showed PRIP interacts with IR. Rab5 silencing rescued surface IR levels in KO cells; dephosphorylation of inhibitory serine residues on IRS-1 was impaired in KO cells.","method":"PRIP double-knockout mouse adipocytes; immunoprecipitation; glucose uptake assay; Western blot for insulin signaling; siRNA knockdown of Rab5; surface IR quantification","journal":"Journal of cell science","confidence":"Medium","confidence_rationale":"Tier 2 — reciprocal co-IP plus KO phenotype with multiple signaling readouts, but PLCL1 and PLCL2 are not genetically separated","pmids":["34859819"],"is_preprint":false},{"year":2025,"finding":"Progesterone receptor (PGR) acts through a putative enhancer located 35 kb upstream of the PLCL2 gene to promote PLCL2 expression in human myometrial cells. PGR occupancy at this locus correlates with PLCL2 mRNA levels, and PGR overexpression increases PLCL2 expression; CRISPRa activation of this enhancer upregulates PLCL2.","method":"H3K27ac/H3K4me1 ChIP-seq (cistrome mapping); chromatin conformation capture; PGR overexpression in myometrial cells; CRISPRa targeting of upstream enhancer; RT-qPCR","journal":"eLife","confidence":"Medium","confidence_rationale":"Tier 2 — multiple orthogonal epigenomic and functional methods linking PGR to PLCL2 transcriptional regulation, single lab","pmids":["40493036"],"is_preprint":false}],"current_model":"PLCL2 is a catalytically inactive PLC-delta-like protein whose PH domain binds PI(4,5)P2 and Ins(1,4,5)P3 at the perinuclear ER; it negatively regulates BCR signaling (suppressing Ca2+ influx, NFATc activation, and ERK activity), acts downstream of progesterone receptor isoform B to suppress uterine myometrial contractility via the Oxtr-PLCL2-Trpc3 pathway, and facilitates insulin receptor surface retention and downstream Akt signaling in adipocytes, with its transcription driven in myometrium by a PGR-occupied upstream enhancer."},"narrative":{"teleology":[{"year":1999,"claim":"Establishing that PLCL2 is a PLC-family member that retains phosphoinositide binding but lacks catalytic activity resolved the question of whether all PLC-like proteins are enzymes, and identified PI(4,5)P2/IP3 binding and perinuclear/ER localization as defining features.","evidence":"Site-directed mutagenesis of catalytic residues, lipid-binding assays, and GFP-fusion localization in C2C12 and COS7 cells","pmids":["10581172"],"confidence":"High","gaps":["No physiological function or signaling pathway had yet been assigned","Mechanism by which PI(4,5)P2 binding without catalysis affects signaling was unknown"]},{"year":2003,"claim":"Genetic deletion of PLCL2 in mice revealed it as a negative regulator of BCR signaling—suppressing Ca²⁺ flux, NFATc activation, and ERK activity—thereby defining its first physiological role as a brake on B cell activation.","evidence":"PLCL2 knockout mouse with calcium flux, NFATc localization, ERK activity, proliferation, and antigen response assays","pmids":["14517301"],"confidence":"High","gaps":["Molecular mechanism by which catalytically dead PLCL2 dampens Ca²⁺ signaling (e.g., PI(4,5)P2 sequestration vs. adaptor function) was not resolved","Whether PLCL2 acts cell-autonomously in B cells was not formally shown"]},{"year":2009,"claim":"PLCL1/PLCL2 double-knockout mice exhibited elevated gonadotropin secretion and impaired female reproduction, extending the functional scope of PLCL2 to neuroendocrine regulation, though individual contributions of the two paralogs remained unresolved.","evidence":"PLCL1/PLCL2 double-knockout mice; serum LH/FSH measurements; pituitary explant cultures; estrous cycle monitoring","pmids":["19553601"],"confidence":"Medium","gaps":["PLCL2-specific contribution was not genetically separated from PLCL1","Molecular targets of PLCL2 in pituitary gonadotrophs were not identified"]},{"year":2021,"claim":"Identification of PLCL2 as a downstream effector of progesterone receptor isoform B in the uterus established a new tissue context and placed PLCL2 within the Oxtr–PLCL2–Trpc3 pathway controlling myometrial contractility.","evidence":"Transgenic PGR-A/PGR-B mouse models; uterine RNA-seq; ex vivo and in vivo contractility assays; CRISPRa gain-of-function","pmids":["33707208"],"confidence":"High","gaps":["Direct biochemical interaction between PLCL2 and Oxtr or Trpc3 was not demonstrated","Whether PLCL2 acts by sequestering phosphoinositides or via protein–protein interactions in myometrium was unclear"]},{"year":2022,"claim":"Demonstration that PLCL2 (together with PLCL1) interacts with the insulin receptor and promotes its surface retention and downstream Akt signaling in adipocytes revealed a metabolic function involving receptor trafficking regulation.","evidence":"PLCL1/PLCL2 double-knockout mouse adipocytes; co-immunoprecipitation with IR; glucose uptake assay; Rab5 siRNA rescue of surface IR","pmids":["34859819"],"confidence":"Medium","gaps":["PLCL2-specific contribution was not genetically separated from PLCL1","Whether PLCL2 binds the IR directly or through an adaptor complex is unresolved","Structural basis of PLCL2–IR interaction is unknown"]},{"year":2025,"claim":"Identification of a PGR-occupied enhancer 35 kb upstream of PLCL2 that drives its transcription in myometrial cells provided the cis-regulatory mechanism linking progesterone signaling to PLCL2 expression.","evidence":"H3K27ac/H3K4me1 ChIP-seq, chromatin conformation capture, PGR overexpression, CRISPRa activation of enhancer in human myometrial cells","pmids":["40493036"],"confidence":"Medium","gaps":["Whether this enhancer operates in other PGR-expressing tissues is unknown","In vivo validation of enhancer necessity (e.g., enhancer deletion mouse) is lacking"]},{"year":null,"claim":"The unifying molecular mechanism by which a catalytically dead PLC-like protein modulates diverse signaling pathways—whether through phosphoinositide sequestration, scaffolding, or competition with active PLCs—remains unresolved.","evidence":"","pmids":[],"confidence":"High","gaps":["No structural model of full-length PLCL2 exists","Relative importance of PI(4,5)P2 binding versus protein–protein interactions for each tissue function is unknown","PLCL2-specific versus PLCL1-redundant functions have not been genetically separated in endocrine and metabolic tissues"]}],"mechanism_profile":{"molecular_activity":[{"term_id":"GO:0008289","term_label":"lipid binding","supporting_discovery_ids":[0]},{"term_id":"GO:0098772","term_label":"molecular function regulator activity","supporting_discovery_ids":[1,3]}],"localization":[{"term_id":"GO:0005783","term_label":"endoplasmic reticulum","supporting_discovery_ids":[0]}],"pathway":[{"term_id":"R-HSA-168256","term_label":"Immune System","supporting_discovery_ids":[1]},{"term_id":"R-HSA-162582","term_label":"Signal Transduction","supporting_discovery_ids":[1,3,4]},{"term_id":"R-HSA-1474165","term_label":"Reproduction","supporting_discovery_ids":[2,3]}],"complexes":[],"partners":["INSR","PLCL1"],"other_free_text":[]},"mechanistic_narrative":"PLCL2 is a catalytically inactive phospholipase C-like protein that functions as a signaling modulator in immune, endocrine, and metabolic contexts. Its PH domain binds PI(4,5)P2 and Ins(1,4,5)P3 and targets the protein to perinuclear/endoplasmic reticulum membranes, but substitution of two essential catalytic residues (His→Thr, Tyr→Phe) abolishes PLC enzymatic activity [PMID:10581172]. In B lymphocytes, PLCL2 negatively regulates BCR signaling by suppressing calcium influx, NFATc nuclear accumulation, and ERK activation, thereby restraining mature B cell proliferation and T-cell-independent antigen responses [PMID:14517301]. In the uterus, PLCL2 is a transcriptional target of progesterone receptor isoform B—driven via a PGR-occupied upstream enhancer—and attenuates myometrial contractility through the Oxtr–PLCL2–Trpc3 axis, while in adipocytes it interacts with the insulin receptor to maintain its surface retention and support downstream Akt signaling [PMID:33707208, PMID:40493036, PMID:34859819]."},"prefetch_data":{"uniprot":{"accession":"Q9UPR0","full_name":"Inactive phospholipase C-like protein 2","aliases":["Phospholipase C-epsilon-2","PLC-epsilon-2"],"length_aa":1127,"mass_kda":125.9,"function":"May play an role in the regulation of Ins(1,4,5)P3 around the endoplasmic reticulum","subcellular_location":"Cytoplasm","url":"https://www.uniprot.org/uniprotkb/Q9UPR0/entry"},"depmap":{"release":"DepMap","has_data":true,"is_common_essential":false,"resolved_as":"","url":"https://depmap.org/portal/gene/PLCL2","classification":"Not Classified","n_dependent_lines":5,"n_total_lines":1208,"dependency_fraction":0.0041390728476821195},"opencell":{"profiled":false,"resolved_as":"","ensg_id":"","cell_line_id":"","localizations":[],"interactors":[],"url":"https://opencell.sf.czbiohub.org/search/PLCL2","total_profiled":1310},"omim":[{"mim_id":"614276","title":"PHOSPHOLIPASE C-LIKE 2; PLCL2","url":"https://www.omim.org/entry/614276"},{"mim_id":"600597","title":"PHOSPHOLIPASE C-LIKE 1; PLCL1","url":"https://www.omim.org/entry/600597"}],"hpa":{"profiled":true,"resolved_as":"","reliability":"","locations":[],"tissue_specificity":"Tissue enhanced","tissue_distribution":"Detected in many","driving_tissues":[{"tissue":"skeletal muscle","ntpm":25.8}],"url":"https://www.proteinatlas.org/search/PLCL2"},"hgnc":{"alias_symbol":["KIAA1092"],"prev_symbol":["PLCE2"]},"alphafold":{"accession":"Q9UPR0","domains":[{"cath_id":"2.30.29.30","chopping":"135-261","consensus_level":"medium","plddt":89.4968,"start":135,"end":261},{"cath_id":"1.10.238.10","chopping":"342-406","consensus_level":"medium","plddt":91.4743,"start":342,"end":406},{"cath_id":"3.20.20.190","chopping":"431-593_610-732","consensus_level":"high","plddt":92.2153,"start":431,"end":732},{"cath_id":"2.60.40.150","chopping":"753-880","consensus_level":"high","plddt":92.1323,"start":753,"end":880},{"cath_id":"-","chopping":"913-1094","consensus_level":"high","plddt":90.9819,"start":913,"end":1094}],"viewer_url":"https://alphafold.ebi.ac.uk/entry/Q9UPR0","model_url":"https://alphafold.ebi.ac.uk/files/AF-Q9UPR0-F1-model_v6.cif","pae_url":"https://alphafold.ebi.ac.uk/files/AF-Q9UPR0-F1-predicted_aligned_error_v6.png","plddt_mean":80.56},"mouse_models":{"mgi_url":"https://www.informatics.jax.org/marker/summary?nomen=PLCL2","jax_strain_url":"https://www.jax.org/strain/search?query=PLCL2"},"sequence":{"accession":"Q9UPR0","fasta_url":"https://rest.uniprot.org/uniprotkb/Q9UPR0.fasta","uniprot_url":"https://www.uniprot.org/uniprotkb/Q9UPR0/entry","alphafold_viewer_url":"https://alphafold.ebi.ac.uk/entry/Q9UPR0"}},"corpus_meta":[{"pmid":"23822953","id":"PMC_23822953","title":"Phosphoproteomics 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(His356→Thr and Tyr552→Phe in the X and Y domains). Its PH domain binds strongly to PI(4,5)P2 and Ins(1,4,5)P3, and moderately to PI(4)P and PI(3,4,5)P3. PLCL2 localizes predominantly to perinuclear areas including the endoplasmic reticulum in myoblast, myotube, and COS7 cells, with the PH domain sufficient for this localization.\",\n      \"method\": \"Site-directed mutagenesis analysis of catalytic residues; lipid-binding assays; GFP-fusion localization in C2C12 and COS7 cells; subcellular fractionation\",\n      \"journal\": \"Biochemical and biophysical research communications\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 — in vitro lipid binding assays, mutagenesis of active-site residues, direct localization with functional domain dissection\",\n      \"pmids\": [\"10581172\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2003,\n      \"finding\": \"PLCL2 functions as a negative regulator of B-cell receptor (BCR) signaling. Genetic knockout of PLCL2 in mice causes hyperproliferation of mature B cells in response to BCR cross-linking, enhanced calcium influx, increased NFATc nuclear accumulation, elevated ERK activity, and a stronger T-cell-independent antigen response, without affecting B2 cell development.\",\n      \"method\": \"PLCL2 knockout mouse model; B cell proliferation assays; calcium flux measurements; NFATc nuclear localization assays; ERK kinase activity assays; antigen response assays\",\n      \"journal\": \"Molecular and cellular biology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 — clean genetic KO with multiple orthogonal functional readouts (Ca2+ flux, transcription factor localization, kinase activity, immune response)\",\n      \"pmids\": [\"14517301\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2009,\n      \"finding\": \"PLCL2 (PRIP-2) and its paralog PLCL1 (PRIP-1) together regulate gonadotropin secretion in females. Double-knockout mice show elevated serum LH and FSH levels and increased LH secretion from explanted anterior pituitary glands, resulting in impaired female reproductive function (smaller uterus, altered estrous cycles, reduced litter size).\",\n      \"method\": \"PLCL1/PLCL2 double-knockout mouse model; serum hormone measurements; explant culture of anterior pituitary glands; estrous cycle monitoring\",\n      \"journal\": \"Biology of reproduction\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — double-KO mouse with defined endocrine phenotype, but PLCL1 and PLCL2 are not genetically separated in this study\",\n      \"pmids\": [\"19553601\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2021,\n      \"finding\": \"Progesterone receptor isoform B (PGR-B) suppresses uterine contractility through a pathway that increases PLCL2 expression while reducing Oxtr and Trpc3 expression. Both PLCL2 and its paralog PLCL1 can attenuate uterine smooth muscle cell contraction when activated by CRISPRa, defining PLCL2 as a downstream effector of PGR-B-mediated myometrial relaxation.\",\n      \"method\": \"Transgenic mouse models overexpressing PGR-A or PGR-B; uterine RNA sequencing; ex vivo and in vivo contractility assays; CRISPRa-based gain-of-function in uterine cells\",\n      \"journal\": \"Proceedings of the National Academy of Sciences of the United States of America\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 — multiple orthogonal methods (transgenic models, RNA-seq, functional contractility assays, CRISPRa) establishing pathway position and functional consequence\",\n      \"pmids\": [\"33707208\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2022,\n      \"finding\": \"PLCL2 (PRIP-2) acts as a positive regulator of insulin signaling in adipocytes by interacting with the insulin receptor (IR) and modulating IR internalization. In PLCL2/PLCL1 double-knockout adipocytes, insulin-stimulated phosphorylation of IR, IRS-1, and Akt is impaired, glucose uptake is reduced, and cell-surface IR is decreased. Co-immunoprecipitation showed PRIP interacts with IR. Rab5 silencing rescued surface IR levels in KO cells; dephosphorylation of inhibitory serine residues on IRS-1 was impaired in KO cells.\",\n      \"method\": \"PRIP double-knockout mouse adipocytes; immunoprecipitation; glucose uptake assay; Western blot for insulin signaling; siRNA knockdown of Rab5; surface IR quantification\",\n      \"journal\": \"Journal of cell science\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — reciprocal co-IP plus KO phenotype with multiple signaling readouts, but PLCL1 and PLCL2 are not genetically separated\",\n      \"pmids\": [\"34859819\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"Progesterone receptor (PGR) acts through a putative enhancer located 35 kb upstream of the PLCL2 gene to promote PLCL2 expression in human myometrial cells. PGR occupancy at this locus correlates with PLCL2 mRNA levels, and PGR overexpression increases PLCL2 expression; CRISPRa activation of this enhancer upregulates PLCL2.\",\n      \"method\": \"H3K27ac/H3K4me1 ChIP-seq (cistrome mapping); chromatin conformation capture; PGR overexpression in myometrial cells; CRISPRa targeting of upstream enhancer; RT-qPCR\",\n      \"journal\": \"eLife\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — multiple orthogonal epigenomic and functional methods linking PGR to PLCL2 transcriptional regulation, single lab\",\n      \"pmids\": [\"40493036\"],\n      \"is_preprint\": false\n    }\n  ],\n  \"current_model\": \"PLCL2 is a catalytically inactive PLC-delta-like protein whose PH domain binds PI(4,5)P2 and Ins(1,4,5)P3 at the perinuclear ER; it negatively regulates BCR signaling (suppressing Ca2+ influx, NFATc activation, and ERK activity), acts downstream of progesterone receptor isoform B to suppress uterine myometrial contractility via the Oxtr-PLCL2-Trpc3 pathway, and facilitates insulin receptor surface retention and downstream Akt signaling in adipocytes, with its transcription driven in myometrium by a PGR-occupied upstream enhancer.\"\n}\n```","stage2_raw":"```json\n{\n  \"mechanistic_narrative\": \"PLCL2 is a catalytically inactive phospholipase C-like protein that functions as a signaling modulator in immune, endocrine, and metabolic contexts. Its PH domain binds PI(4,5)P2 and Ins(1,4,5)P3 and targets the protein to perinuclear/endoplasmic reticulum membranes, but substitution of two essential catalytic residues (His→Thr, Tyr→Phe) abolishes PLC enzymatic activity [PMID:10581172]. In B lymphocytes, PLCL2 negatively regulates BCR signaling by suppressing calcium influx, NFATc nuclear accumulation, and ERK activation, thereby restraining mature B cell proliferation and T-cell-independent antigen responses [PMID:14517301]. In the uterus, PLCL2 is a transcriptional target of progesterone receptor isoform B—driven via a PGR-occupied upstream enhancer—and attenuates myometrial contractility through the Oxtr–PLCL2–Trpc3 axis, while in adipocytes it interacts with the insulin receptor to maintain its surface retention and support downstream Akt signaling [PMID:33707208, PMID:40493036, PMID:34859819].\",\n  \"teleology\": [\n    {\n      \"year\": 1999,\n      \"claim\": \"Establishing that PLCL2 is a PLC-family member that retains phosphoinositide binding but lacks catalytic activity resolved the question of whether all PLC-like proteins are enzymes, and identified PI(4,5)P2/IP3 binding and perinuclear/ER localization as defining features.\",\n      \"evidence\": \"Site-directed mutagenesis of catalytic residues, lipid-binding assays, and GFP-fusion localization in C2C12 and COS7 cells\",\n      \"pmids\": [\"10581172\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\n        \"No physiological function or signaling pathway had yet been assigned\",\n        \"Mechanism by which PI(4,5)P2 binding without catalysis affects signaling was unknown\"\n      ]\n    },\n    {\n      \"year\": 2003,\n      \"claim\": \"Genetic deletion of PLCL2 in mice revealed it as a negative regulator of BCR signaling—suppressing Ca²⁺ flux, NFATc activation, and ERK activity—thereby defining its first physiological role as a brake on B cell activation.\",\n      \"evidence\": \"PLCL2 knockout mouse with calcium flux, NFATc localization, ERK activity, proliferation, and antigen response assays\",\n      \"pmids\": [\"14517301\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\n        \"Molecular mechanism by which catalytically dead PLCL2 dampens Ca²⁺ signaling (e.g., PI(4,5)P2 sequestration vs. adaptor function) was not resolved\",\n        \"Whether PLCL2 acts cell-autonomously in B cells was not formally shown\"\n      ]\n    },\n    {\n      \"year\": 2009,\n      \"claim\": \"PLCL1/PLCL2 double-knockout mice exhibited elevated gonadotropin secretion and impaired female reproduction, extending the functional scope of PLCL2 to neuroendocrine regulation, though individual contributions of the two paralogs remained unresolved.\",\n      \"evidence\": \"PLCL1/PLCL2 double-knockout mice; serum LH/FSH measurements; pituitary explant cultures; estrous cycle monitoring\",\n      \"pmids\": [\"19553601\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"PLCL2-specific contribution was not genetically separated from PLCL1\",\n        \"Molecular targets of PLCL2 in pituitary gonadotrophs were not identified\"\n      ]\n    },\n    {\n      \"year\": 2021,\n      \"claim\": \"Identification of PLCL2 as a downstream effector of progesterone receptor isoform B in the uterus established a new tissue context and placed PLCL2 within the Oxtr–PLCL2–Trpc3 pathway controlling myometrial contractility.\",\n      \"evidence\": \"Transgenic PGR-A/PGR-B mouse models; uterine RNA-seq; ex vivo and in vivo contractility assays; CRISPRa gain-of-function\",\n      \"pmids\": [\"33707208\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\n        \"Direct biochemical interaction between PLCL2 and Oxtr or Trpc3 was not demonstrated\",\n        \"Whether PLCL2 acts by sequestering phosphoinositides or via protein–protein interactions in myometrium was unclear\"\n      ]\n    },\n    {\n      \"year\": 2022,\n      \"claim\": \"Demonstration that PLCL2 (together with PLCL1) interacts with the insulin receptor and promotes its surface retention and downstream Akt signaling in adipocytes revealed a metabolic function involving receptor trafficking regulation.\",\n      \"evidence\": \"PLCL1/PLCL2 double-knockout mouse adipocytes; co-immunoprecipitation with IR; glucose uptake assay; Rab5 siRNA rescue of surface IR\",\n      \"pmids\": [\"34859819\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"PLCL2-specific contribution was not genetically separated from PLCL1\",\n        \"Whether PLCL2 binds the IR directly or through an adaptor complex is unresolved\",\n        \"Structural basis of PLCL2–IR interaction is unknown\"\n      ]\n    },\n    {\n      \"year\": 2025,\n      \"claim\": \"Identification of a PGR-occupied enhancer 35 kb upstream of PLCL2 that drives its transcription in myometrial cells provided the cis-regulatory mechanism linking progesterone signaling to PLCL2 expression.\",\n      \"evidence\": \"H3K27ac/H3K4me1 ChIP-seq, chromatin conformation capture, PGR overexpression, CRISPRa activation of enhancer in human myometrial cells\",\n      \"pmids\": [\"40493036\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"Whether this enhancer operates in other PGR-expressing tissues is unknown\",\n        \"In vivo validation of enhancer necessity (e.g., enhancer deletion mouse) is lacking\"\n      ]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"The unifying molecular mechanism by which a catalytically dead PLC-like protein modulates diverse signaling pathways—whether through phosphoinositide sequestration, scaffolding, or competition with active PLCs—remains unresolved.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"High\",\n      \"gaps\": [\n        \"No structural model of full-length PLCL2 exists\",\n        \"Relative importance of PI(4,5)P2 binding versus protein–protein interactions for each tissue function is unknown\",\n        \"PLCL2-specific versus PLCL1-redundant functions have not been genetically separated in endocrine and metabolic tissues\"\n      ]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0008289\", \"supporting_discovery_ids\": [0]},\n      {\"term_id\": \"GO:0098772\", \"supporting_discovery_ids\": [1, 3]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0005783\", \"supporting_discovery_ids\": [0]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"R-HSA-168256\", \"supporting_discovery_ids\": [1]},\n      {\"term_id\": \"R-HSA-162582\", \"supporting_discovery_ids\": [1, 3, 4]},\n      {\"term_id\": \"R-HSA-1474165\", \"supporting_discovery_ids\": [2, 3]}\n    ],\n    \"complexes\": [],\n    \"partners\": [\n      \"INSR\",\n      \"PLCL1\"\n    ],\n    \"other_free_text\": []\n  }\n}\n```"}