title: Cardiolipin synthase is required for Streptomyces coelicolor morphogenesis.
abstract: The fluid mosaic model has recently been amended to account for the existence of membrane domains enriched in certain phospholipids. In rod-shaped bacteria, the anionic phospholipid cardiolipin is enriched at the cell poles but its role in the morphogenesis of the filamentous bacterium Streptomyces coelicolor is unknown. It was impossible to delete clsA (cardiolipin synthase; SCO1389) unless complemented by a second copy of clsA elsewhere in the chromosome. When placed under the control of an inducible promoter, clsA expression, phospholipid profile and morphogenesis became inducer dependent. TLC analysis of phospholipid showed altered profiles upon depletion of clsA expression. Analysis of cardiolipin by mass spectrometry showed two distinct cardiolipin envelopes that reflected differences in acyl chain length; the level of the larger cardiolipin envelope was reduced in concert with clsA expression. ClsA-EGFP did not localize to specific locations, but cardiolipin itself showed enrichment at hyphal tips, branch points and anucleate regions. Quantitative analysis of hyphal dimensions showed that the mycelial architecture and the erection of aerial hyphae were affected by the expression of clsA. Overexpression of clsA resulted in weakened hyphal tips, misshaped aerial hyphae and anucleate spores and demonstrates that cardiolipin synthesis is a requirement for morphogenesis in Streptomyces.
authors.affiliation: Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, 161 Cathedral Street, Glasgow G4 0RE, UK.
authors.forename: Vinod
authors.initials: V
authors.lastname: Jyothikumar
authors.forename: Khanungkan
authors.initials: K
authors.lastname: Klanbut
authors.forename: John
authors.initials: J
authors.lastname: Tiong
authors.forename: James S
authors.initials: JS
authors.lastname: Roxburgh
authors.forename: Iain S
authors.initials: IS
authors.lastname: Hunter
authors.forename: Terry K
authors.initials: TK
authors.lastname: Smith
authors.forename: Paul R
authors.initials: PR
authors.lastname: Herron
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D002308:Cardiolipins / Q000378:metabolism; D015964:Gene Expression Regulation, Bacterial; D020043:Genes, Essential; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D009154:Mutation; D011401:Promoter Regions, Genetic; D048372:Streptomyces coelicolor / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development*; D017855:Transferases (Other Substituted Phosphate Groups) / Q000235:genetics / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D002308:Cardiolipins; D008565:Membrane Proteins; D017855:Transferases (Other Substituted Phosphate Groups); C100091:cardiolipin synthetase