{"doi":"10.17615/91b8-gp61","title":"RhoA Activates Purified Phospholipase C-ϵ by a Guanine Nucleotide-dependent Mechanism","abstract":"Phospholipase C-epsilon (PLC-epsilon) is a recently identified PLC isoform activated by subunits of heterotrimeric G proteins (Galpha(12), Galpha(13), and Gbetagamma) as well as by the low molecular weight GTPases, Rho and Ras. To define the enzymatic activity and substrate specificity of PLC-epsilon as well as its potential direct activation by Rho family GTPases, a major fragment of PLC-epsilon encompassing the catalytic core (EF-hand repeats through the tandem Ras-associating domains; approximately 118 kDa) was purified to near homogeneity and assayed after reconstitution under various conditions. Similar to the enzymatic profiles of previously purified PLC-beta isozymes, the purified fragment of PLC-epsilon maximally hydrolyzed phosphatidylinositol 4-phosphate at a rate of approximately 10 mumol/mg of protein/min, exhibited phospholipase activity dependent on the concentration of free calcium, and favored phosphatidylinositol 4,5-bisphosphate as substrate relative to other phosphoinositides. Furthermore, in mixed detergent phospholipid micelles, RhoA stimulated the phospholipase activity of the PLC-epsilon fragment in both a concentration-dependent and guanosine 5'-O-(3-thiotriphosphate)-dependent manner. This activation was abolished by the deletion of a unique approximately 65 amino acid-insert within the catalytic core of PLC-epsilon. Although Rac1 activated purified PLC-beta2ina guanine nucleotide-dependent manner, Rac1 failed to promote guanine nucleotide-dependent activation of purified PLC-epsilon. These results indicate that PLC-epsilon is a direct downstream effector for RhoA and that RhoA-dependent activation of PLC-epsilon depends on a unique insert within the catalytic core of the phospholipase.","journal":"UNC Libraries","year":2021,"id":230423,"datarank":0.0,"base_score":0.0,"endowment":0.0,"self_citation_contribution":0.0,"citation_network_contribution":0.0,"self_endowment_contribution":0.0,"citer_contribution":0.0,"corpus_percentile":null,"corpus_rank":null,"citation_count":0,"citer_count":0,"citers_with_citation_signal":0,"citers_with_endowment":0,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":0.9566,"is_data_producer":false,"deposit_databanks":null,"is_oa":true,"file_count":0,"downloads":0,"has_version_chain":false,"published_date":"2021-01-01","fair_score":null,"fair_percentile":null,"algorithm_id":"datarank_citation_only_1hop_v6","ranking_scope":"data_only","authors":[{"id":604905,"name":"Svetlana Gershburg","orcid":null,"position":1,"is_corresponding":false},{"id":836128,"name":"Michele R. Wing","orcid":"0000-0001-9688-0396","position":2,"is_corresponding":false},{"id":605180,"name":"Jason P. Seifert","orcid":null,"position":3,"is_corresponding":false},{"id":602827,"name":"Jason T. Snyder","orcid":null,"position":4,"is_corresponding":false},{"id":515775,"name":"T. Kendall Harden","orcid":null,"position":5,"is_corresponding":false},{"id":30214,"name":"John Sondek","orcid":"0000-0002-1127-8310","position":0,"is_corresponding":true}],"reference_count":0,"raw_metadata":null,"created_at":"2026-07-18T23:55:05.844766Z","pmid":null,"pmcid":null,"fwci":null,"citation_percentile":null,"influential_citations":0,"oa_status":null,"license":null,"views":0,"total_file_size_bytes":0,"version_count":0,"fair_f":null,"fair_a":null,"fair_i":null,"fair_r":null,"fair_zscore":null,"fair_rationale":null,"fair_model":null,"fair_agent_version":null,"fair_fulltext_source":null,"fair_has_llm":null,"fair_computed_at":null,"clinical_trials":[],"software_tools":[],"db_accessions":[],"linked_datasets":[],"topics":[]}