{"doi":"10.1101/2025.04.28.651061","title":"A light-induced microprotein triggers regulated intramembrane proteolysis to promote photo sensing in a pathogenic bacterium","abstract":"ABSTRACT Light, a ubiquitous environmental stimulus, shapes behavior and physiology across all domains of life. While photoreceptors are widespread in bacterial genomes, their functional roles and signal transduction mechanisms in non-photosynthetic bacteria remain understudied. Light represses biofilms and virulence factors through a bacteriophytochrome photoreceptor BphP and response regulator AlgB in the human pathogen Pseudomonas aeruginosa . Here, we used transposon mutagenesis screening to identify a conserved hypothetical microprotein, DimA, as the master activator of the photo-sensing cascade. Transcriptomics, luciferase reporter assays and physiological assays revealed that deletion of dimA abolishes light-dependent suppression of virulence factors and biofilms. Mechanistically, we demonstrated that DimA activates the site-I protease AlgW, triggering regulated intramembrane proteolysis of the anti-sigma factor MucA, liberating sigma factor AlgU (σ22), which promotes algB expression. We discovered a positive feedback loop where light-activated AlgB upregulates dimA expression, thereby amplifying the photosensory response. This work establishes DimA as a crucial activator of photo sensing and expands our understanding of bacterial adaptation to changing light environments.","journal":"bioRxiv (Cold Spring Harbor Laboratory)","year":2025,"id":565091,"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":0.9471,"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":274908,"name":"Jonathan D. Winkelman","orcid":"0000-0002-8870-2917","position":1,"is_corresponding":false},{"id":1468640,"name":"Gong Chen","orcid":"0009-0000-6477-381X","position":2,"is_corresponding":false},{"id":649282,"name":"Sampriti Mukherjee","orcid":"0000-0002-5509-8776","position":3,"is_corresponding":false},{"id":1443435,"name":"Dimitrios Manias","orcid":"0000-0002-7611-3533","position":0,"is_corresponding":true}],"reference_count":71,"raw_metadata":null,"created_at":"2026-07-19T02:56:28.709936Z","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":[]}