{"doi":"10.1126/scisignal.ado1252","title":"Conditional requirement for dimerization of the membrane-binding module for BTK signaling in lymphocyte cell lines","abstract":"Bruton's tyrosine kinase (BTK) is a major drug target in immune cells. The membrane-binding pleckstrin homology and tec homology (PH-TH) domains of BTK are required for signaling. Dimerization of the PH-TH module strongly stimulates the kinase activity of BTK in vitro. Here, we investigated whether BTK dimerizes in cells using the PH-TH module and whether this dimerization is necessary for signaling. To address this question, we developed high-throughput mutagenesis assays for BTK function in Ramos B cells and Jurkat T cells. We measured the fitness costs for thousands of point mutations in the PH-TH module and kinase domain to assess whether dimerization of the PH-TH module and BTK kinase activity were necessary for function. In Ramos cells, we found that neither PH-TH dimerization nor kinase activity was required for BTK signaling. Instead, in Ramos cells, BTK signaling was enhanced by PH-TH module mutations that increased membrane adsorption, even at the cost of reduced PH-TH dimerization. In contrast, in Jurkat cells, we found that BTK signaling depended on both PH-TH dimerization and kinase activity. Evolutionary analysis indicated that BTK proteins in organisms that evolved before the divergence of ray-finned fishes lacked PH-TH dimerization but had active kinase domains, similar to other Tec family kinases. Thus, PH-TH dimerization is a distinct feature of BTK that evolved to exert stricter regulatory control on kinase activity as adaptive immune systems gained increased complexity.","journal":"Science Signaling","year":2025,"id":518844,"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":6,"citer_count":0,"citers_with_citation_signal":0,"citers_with_endowment":0,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":0.9559,"is_data_producer":false,"deposit_databanks":null,"is_oa":true,"file_count":0,"downloads":0,"has_version_chain":false,"published_date":"2025-01-01","fair_score":null,"fair_percentile":null,"algorithm_id":"datarank_citation_only_1hop_v6","ranking_scope":"data_only","authors":[{"id":1193299,"name":"Sam Ghaffari-Kashani","orcid":"0009-0001-0711-6562","position":1,"is_corresponding":false},{"id":1386755,"name":"Chien‐Lun Hung","orcid":"0000-0002-2546-1132","position":2,"is_corresponding":false},{"id":302378,"name":"Jay T. Groves","orcid":"0000-0002-3037-5220","position":3,"is_corresponding":false},{"id":344120,"name":"Arthur Weiss","orcid":"0000-0002-2414-9024","position":4,"is_corresponding":false},{"id":344888,"name":"John Kuriyan","orcid":"0000-0002-4414-5477","position":5,"is_corresponding":false},{"id":247716,"name":"Timothy J. Eisen","orcid":"0000-0002-4812-4171","position":0,"is_corresponding":true}],"reference_count":83,"raw_metadata":null,"created_at":"2026-07-19T02:49:14.184995Z","pmid":"39808693","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":[]}