title: The Myxococcus xanthus spore cuticula protein C is a fragment of FibA, an extracellular metalloprotease produced exclusively in aggregated cells.
abstract: Myxococcus xanthus is a soil bacterium with a complex life cycle involving distinct cell fates, including production of environmentally resistant spores to withstand periods of nutrient limitation. Spores are surrounded by an apparently self-assembling cuticula containing at least Proteins S and C; the gene encoding Protein C is unknown. During analyses of cell heterogeneity in M. xanthus, we observed that Protein C accumulated exclusively in cells found in aggregates. Using mass spectrometry analysis of Protein C either isolated from spore cuticula or immunoprecipitated from aggregated cells, we demonstrate that Protein C is actually a proteolytic fragment of the previously identified but functionally elusive zinc metalloprotease, FibA. Subpopulation specific FibA accumulation is not due to transcriptional regulation suggesting post-transcriptional regulation mechanisms mediate its heterogeneous accumulation patterns.
authors.affiliation: Department of Ecophysiology, Max Planck Institute for Terrestrial Microbiology, Marburg, Germany.
authors.forename: Bongsoo
authors.initials: B
authors.lastname: Lee
authors.forename: Petra
authors.initials: P
authors.lastname: Mann
authors.forename: Vidhi
authors.initials: V
authors.lastname: Grover
authors.forename: Anke
authors.initials: A
authors.lastname: Treuner-Lange
authors.forename: Jörg
authors.initials: J
authors.lastname: Kahnt
authors.forename: Penelope I
authors.initials: PI
authors.lastname: Higgs
mesh_terms: D000942:Antigens, Bacterial / Q000737:chemistry / Q000378:metabolism*; D005110:Extracellular Space / Q000201:enzymology*; D015964:Gene Expression Regulation, Bacterial; D013058:Mass Spectrometry; D008565:Membrane Proteins / Q000737:chemistry / Q000378:metabolism*; D045726:Metalloproteases / Q000737:chemistry / Q000378:metabolism*; D008970:Molecular Weight; D016941:Myxococcus xanthus / Q000166:cytology* / Q000201:enzymology* / Q000235:genetics / Q000502:physiology; D010446:Peptide Fragments / Q000378:metabolism*; D011401:Promoter Regions, Genetic / Q000235:genetics; D011486:Protein C / Q000737:chemistry / Q000378:metabolism*; D013171:Spores, Bacterial / Q000166:cytology / Q000201:enzymology / Q000235:genetics; D013347:Subcellular Fractions / Q000378:metabolism; D014158:Transcription, Genetic
chemical_list: D000942:Antigens, Bacterial; D008565:Membrane Proteins; D010446:Peptide Fragments; D011486:Protein C; C118696:fibA protein, bacteria; D045726:Metalloproteases