PMID- 26283769 OWN - NLM STAT- MEDLINE DCOM- 20160108 LR - 20181113 IS - 1098-5530 (Electronic) IS - 0021-9193 (Print) IS - 0021-9193 (Linking) VI - 197 IP - 21 DP - 2015 Nov TI - The Bacterial Tyrosine Kinase Activator TkmA Contributes to Biofilm Formation Largely Independently of the Cognate Kinase PtkA in Bacillus subtilis. PG - 3421-32 LID - 10.1128/JB.00438-15 [doi] AB - In Bacillus subtilis, biosynthesis of exopolysaccharide (EPS), a key biofilm matrix component, is regulated at the posttranslational level by the bacterial tyrosine kinase (BY-kinase) EpsB. EpsB, in turn, relies on the cognate kinase activator EpsA for activation. A concerted role of a second BY-kinase-kinase activator pair, PtkA and TkmA, respectively in biofilm formation was also indicated in previous studies. However, the exact functions of PtkA and TkmA in biofilm formation remain unclear. In this work, we show that the kinase activator TkmA contributes to biofilm formation largely independently of the cognate kinase, PtkA. We further show that the biofilm defect caused by a DeltatkmA mutation can be rescued by complementation by epsA, suggesting a functional overlap between TkmA and EpsA and providing a possible explanation for the role of TkmA in biofilm formation. We also show that the importance of TkmA in biofilm formation depends largely on medium conditions; the biofilm defect of DeltatkmA is very severe in the biofilm medium LBGM (lysogenic broth [LB] supplemented with 1% [vol/vol] glycerol and 100 muM MnSO4) but marginal in another commonly used biofilm medium, MSgg (5 mM potassium phosphate [pH 7.0], MOPS [100 mM morpholinepropanesulfonic acid] [pH 7.0], 2 mM MgCl2, 700 muM CaCl2, 50 muM MnCl2, 50 muM FeCl3, 1 muM ZnCl2, 2 muM thiamine, 0.5% glycerol, 0.5% glutamic acid, 50 mug/ml tryptophan, 50 mug/ml threonine, and 50 mug/ml phenylalanine). The molecular basis for the medium dependence is likely due to differential expression of tkmA and epsA in the two different media and complex regulation of these genes by both Spo0A and DegU. Our studies provide genetic evidence for possible cross talk between a BY-kinase activator (TkmA) and a noncognate kinase (EpsB) and an example of how environmental conditions may influence such cross talk in regulating biofilm formation in B. subtilis. IMPORTANCE: In bacteria, biosynthesis of secreted polysaccharides is often regulated by bacterial tyrosine kinases (BY-kinases). BY-kinases, in turn, rely on cognate kinase activators for activation. In this study, we investigated the role of a BY-kinase activator in biofilm formation in Bacillus subtilis. We present evidence that different BY-kinase activators may functionally overlap each other, as well as an example of how activities of the BY-kinase activators may be highly dependent on environmental conditions. Our study broadens the understanding of the complexity of regulation of the BY-kinases/kinase activators and the influence on bacterial cell physiology. CI - Copyright (c) 2015, American Society for Microbiology. All Rights Reserved. FAU - Gao, Tantan AU - Gao T AD - Department of Plant Pathology, College of Agronomy and Biotechnology, China Agricultural University, Beijing, China Department of Biology, Northeastern University, Boston, Massachusetts, USA Department of Molecular and Cellular Biology, Harvard University, Cambridge, Massachusetts, USA. FAU - Greenwich, Jennifer AU - Greenwich J AD - Department of Biology, Northeastern University, Boston, Massachusetts, USA. FAU - Li, Yan AU - Li Y AD - Department of Plant Pathology, College of Agronomy and Biotechnology, China Agricultural University, Beijing, China. FAU - Wang, Qi AU - Wang Q AD - Department of Plant Pathology, College of Agronomy and Biotechnology, China Agricultural University, Beijing, China Wangqi@cau.edu.cn y.chai@neu.edu. FAU - Chai, Yunrong AU - Chai Y AD - Department of Biology, Northeastern University, Boston, Massachusetts, USA Wangqi@cau.edu.cn y.chai@neu.edu. LA - eng PT - Journal Article PT - Research Support, Non-U.S. Gov't DEP - 20150817 PL - United States TA - J Bacteriol JT - Journal of bacteriology JID - 2985120R RN - 0 (Bacterial Proteins) RN - EC 2.7.10.1 (Protein-Tyrosine Kinases) SB - IM MH - Bacillus subtilis/*enzymology/genetics/physiology MH - Bacterial Proteins/genetics/*metabolism MH - Base Sequence MH - *Biofilms MH - *Gene Expression Regulation, Bacterial MH - Molecular Sequence Data MH - Protein-Tyrosine Kinases/genetics/*metabolism PMC - PMC4621062 EDAT- 2015/08/19 06:00 MHDA- 2016/01/09 06:00 PMCR- 2016/05/01 CRDT- 2015/08/19 06:00 PHST- 2015/06/02 00:00 [received] PHST- 2015/08/12 00:00 [accepted] PHST- 2015/08/19 06:00 [entrez] PHST- 2015/08/19 06:00 [pubmed] PHST- 2016/01/09 06:00 [medline] PHST- 2016/05/01 00:00 [pmc-release] AID - JB.00438-15 [pii] AID - 00438-15 [pii] AID - 10.1128/JB.00438-15 [doi] PST - ppublish SO - J Bacteriol. 2015 Nov;197(21):3421-32. doi: 10.1128/JB.00438-15. Epub 2015 Aug 17.