{"doi":"10.3389/fcell.2024.1473210","title":"Transcriptional regulation in the absence of inositol trisphosphate receptor calcium signaling","abstract":"The activation of IP 3 receptor (IP 3 R) Ca 2+ channels generates agonist-mediated Ca 2+ signals that are critical for the regulation of a wide range of biological processes. It is therefore surprising that CRISPR induced loss of all three IP 3 R isoforms (TKO) in HEK293 and HeLa cell lines yields cells that can survive, grow and divide, albeit more slowly than wild-type cells. In an effort to understand the adaptive mechanisms involved, we have examined the activity of key Ca 2+ dependent transcription factors (NFAT, CREB and AP-1) and signaling pathways using luciferase-reporter assays, phosphoprotein immunoblots and whole genome transcriptomic studies. In addition, the diacylglycerol arm of the signaling pathway was investigated with protein kinase C (PKC) inhibitors and siRNA knockdown. The data showed that agonist-mediated NFAT activation was lost but CREB activation was maintained in IP 3 R TKO cells. Under base-line conditions transcriptome analysis indicated the differential expression of 828 and 311 genes in IP 3 R TKO HEK293 or HeLa cells, respectively, with only 18 genes being in common. Three main adaptations in TKO cells were identified in this study: 1) increased basal activity of NFAT, CREB and AP-1; 2) an increased reliance on Ca 2+ - insensitive PKC isoforms; and 3) increased production of reactive oxygen species and upregulation of antioxidant defense enzymes. We suggest that whereas wild-type cells rely on a Ca 2+ and DAG signal to respond to stimuli, the TKO cells utilize the adaptations to allow key signaling pathways (e.g., PKC, Ras/MAPK, CREB) to transition to the activated state using a DAG signal alone.","journal":"Frontiers in Cell and Developmental Biology","year":2024,"id":507126,"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":0.9567,"is_data_producer":false,"deposit_databanks":null,"is_oa":true,"file_count":0,"downloads":0,"has_version_chain":false,"published_date":"2024-01-01","fair_score":null,"fair_percentile":null,"algorithm_id":"datarank_citation_only_1hop_v6","ranking_scope":"data_only","authors":[{"id":713469,"name":"David M. Booth","orcid":null,"position":1,"is_corresponding":false},{"id":1358455,"name":"David Smith","orcid":"0000-0001-5495-7981","position":2,"is_corresponding":false},{"id":1169699,"name":"Marco Tigano","orcid":"0000-0002-4353-9220","position":3,"is_corresponding":false},{"id":316832,"name":"György Hajnóczky","orcid":"0000-0003-3813-2570","position":4,"is_corresponding":false},{"id":712694,"name":"Suresh K. Joseph","orcid":"0000-0002-2991-3458","position":5,"is_corresponding":false},{"id":467238,"name":"Michael Young","orcid":"0009-0006-1832-3635","position":0,"is_corresponding":true}],"reference_count":90,"raw_metadata":null,"created_at":"2026-07-19T02:10:58.484528Z","pmid":"39712573","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":[]}