{"doi":"10.1016/j.jbc.2025.110361","title":"Proton gradient controls the lateral rearrangement of inner membrane domains in response to membrane fluidizer stress in Mycobacterium smegmatis","abstract":"Mycobacterium smegmatis partitions its plasma membrane into two distinct regions: the inner membrane domain (IMD) and the conventional plasma membrane. IMD, enriched in the sub-polar regions of actively growing rod-shaped cell, contains many membrane proteins involved in cell envelope biosynthesis. Dibucaine, a membrane fluidizer, disrupts plasma membrane integrity and de-partitions the IMD from the sub-polar regions. We do not know what governs the de-partitioning of the IMD in response to dibucaine stress. In this study, we investigated the stress response of the IMD under respiration defect. We first depleted MenG, a key enzyme in the menaquinone biosynthesis, by CRISPRi and observed that the IMD does not respond to dibucaine-induced membrane stress. CRISPRi-induced knockdown of qcrC , a gene encoding a component of an electron transport chain cytochrome, corroborated the results of menG knockdown. In contrast, neither CRISPRi knockdown of atpD , a gene encoding a component of the ATP synthase nor inhibition of ATP synthase by bedaquiline inhibited the dibucaine-induced de-partitioning of sub-polar IMD as robustly as CRISPRi knockdowns of menG and qcrC . A pretreatment with the protonophore carbonyl cyanide m -chlorophenyl hydrazone (CCCP) prevented dibucaine-induced IMD de-partitioning. Furthermore, a pretreatment with nigericin, which acts as a H + /K + antiporter and disrupts the proton gradient without affecting membrane potential, also inhibited the IMD de-partitioning in a way similar to CCCP. Taken together, our findings suggest that membrane stress-induced IMD delocalization is not a passive lipid dispersion but an active membrane rearrangement dependent on an electrochemical gradient of proton.","journal":"Journal of Biological Chemistry","year":2025,"id":532518,"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":3,"citer_count":0,"citers_with_citation_signal":0,"citers_with_endowment":0,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":0.9443,"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":1414069,"name":"Shivangi","orcid":null,"position":1,"is_corresponding":false},{"id":336889,"name":"Joel S. Freundlich","orcid":"0000-0002-3411-3455","position":2,"is_corresponding":false},{"id":678337,"name":"Yasu S Morita","orcid":"0000-0002-4514-9242","position":3,"is_corresponding":false},{"id":767692,"name":"Malavika Prithviraj","orcid":null,"position":0,"is_corresponding":true}],"reference_count":45,"raw_metadata":null,"created_at":"2026-07-19T02:51:23.237536Z","pmid":"40513951","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":[]}