{"doi":"10.1101/2020.10.06.328708","title":"Clustering-based positive feedback between a kinase and its substrate enables effective T-cell receptor signaling","abstract":"Abstract Protein clusters and condensates are pervasive in mammalian signaling. Yet how the signaling capacity of higher-order assemblies differs from simpler forms of molecular organization is still poorly understood. Here, we present an optogenetic approach to switch between light-induced clusters and simple protein heterodimers with a single point mutation. We apply this system to study how clustering affects signaling from the kinase Zap70 and its substrate LAT, proteins that normally form membrane-localized clusters during T cell activation. We find that light-induced clusters of LAT and Zap70 trigger potent activation of downstream signaling pathways even in non-T cells, whereas one-to-one dimers do not. We provide evidence that clusters harbor a local positive feedback loop between three components: Zap70, LAT, and Src-family kinases that bind to phosphorylated LAT and further activate Zap70. Overall, our study provides evidence for a specific role of protein condensates in cell signaling, and identifies a simple biochemical circuit that can robustly sense protein oligomerization state. Highlights - A general system for studying the role of protein clusters versus dimers. - Membrane clusters of the kinase Zap70 and its substrate LAT trigger potent downstream signaling. - Clustering Zap70 with LAT is required for full activation of Zap70 kinase activity. - A positive feedback loop connects phosphorylated LAT to Zap70 activation via Src-family kinases.","journal":"bioRxiv (Cold Spring Harbor Laboratory)","year":2020,"id":131267,"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":0.9594,"is_data_producer":false,"deposit_databanks":null,"is_oa":true,"file_count":0,"downloads":0,"has_version_chain":false,"published_date":"2020-01-01","fair_score":null,"fair_percentile":null,"algorithm_id":"datarank_citation_only_1hop_v6","ranking_scope":"data_only","authors":[{"id":321433,"name":"Ellen H. Reed","orcid":"0000-0002-8187-0934","position":1,"is_corresponding":false},{"id":256397,"name":"Jared E. Toettcher","orcid":"0000-0002-1546-4030","position":2,"is_corresponding":false},{"id":584714,"name":"Elliot Dine","orcid":"0000-0002-6795-7195","position":0,"is_corresponding":true}],"reference_count":59,"raw_metadata":null,"created_at":"2026-07-18T23:16:00.235845Z","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":[]}