title: Cyclic-di-AMP synthesis by the diadenylate cyclase CdaA is modulated by the peptidoglycan biosynthesis enzyme GlmM in Lactococcus lactis.
abstract: The second messenger cyclic-di-adenosine monophosphate (c-di-AMP) plays important roles in growth, virulence, cell wall homeostasis, potassium transport and affects resistance to antibiotics, heat and osmotic stress. Most Firmicutes contain only one c-di-AMP synthesizing diadenylate cyclase (CdaA); however, little is known about signals and effectors controlling CdaA activity and c-di-AMP levels. In this study, a genetic screen was employed to identify components which affect the c-di-AMP level in Lactococcus. We characterized suppressor mutations that restored osmoresistance to spontaneous c-di-AMP phosphodiesterase gdpP mutants, which contain high c-di-AMP levels. Loss-of-function and gain-of-function mutations were identified in the cdaA and gdpP genes, respectively, which led to lower c-di-AMP levels. A mutation was also identified in the phosphoglucosamine mutase gene glmM, which is commonly located within the cdaA operon in bacteria. The glmM I154F mutation resulted in a lowering of the c-di-AMP level and a reduction in the key peptidoglycan precursor UDP-N-acetylglucosamine in L. lactis. C-di-AMP synthesis by CdaA was shown to be inhibited by GlmM(I154F) more than GlmM and GlmM(I154F) was found to bind more strongly to CdaA than GlmM. These findings identify GlmM as a c-di-AMP level modulating protein and provide a direct connection between c-di-AMP synthesis and peptidoglycan biosynthesis.
authors.affiliation: School of Agriculture and Food Sciences, University of Queensland, Brisbane, Queensland, Australia.
authors.forename: Yan
authors.initials: Y
authors.lastname: Zhu
authors.affiliation: School of Agriculture and Food Sciences, University of Queensland, Brisbane, Queensland, Australia.|University of Science and Technology, The University of Danang, Da Nang, Vietnam.
authors.forename: Thi Huong
authors.initials: TH
authors.lastname: Pham
authors.affiliation: School of Agriculture and Food Sciences, University of Queensland, Brisbane, Queensland, Australia.
authors.forename: Thi Hanh Nguyen
authors.initials: TH
authors.lastname: Nhiep
authors.affiliation: School of Agriculture and Food Sciences, University of Queensland, Brisbane, Queensland, Australia.
authors.forename: Ngoc Minh Thu
authors.initials: NM
authors.lastname: Vu
authors.affiliation: Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, Brisbane, Queensland, Australia.
authors.forename: Esteban
authors.initials: E
authors.lastname: Marcellin
authors.affiliation: School of Biological Sciences, Nanyang Technological University, Singapore, Singapore.
authors.forename: Alolika
authors.initials: A
authors.lastname: Chakrabortti
authors.affiliation: College of Food Science and Technology, Hunan Agricultural University, Changsha, Hunan Province, China.
authors.forename: Yuanliang
authors.initials: Y
authors.lastname: Wang
authors.affiliation: School of Agriculture and Food Sciences, University of Queensland, Brisbane, Queensland, Australia.
authors.forename: Jennifer
authors.initials: J
authors.lastname: Waanders
authors.affiliation: School of Agriculture and Food Sciences, University of Queensland, Brisbane, Queensland, Australia.
authors.forename: Raquel
authors.initials: R
authors.lastname: Lo
authors.affiliation: School of Life Sciences, University of Technology Sydney, Sydney, New South Wales, Australia.
authors.forename: Wilhelmina M
authors.initials: WM
authors.lastname: Huston
authors.affiliation: School of Agriculture and Food Sciences, University of Queensland, Brisbane, Queensland, Australia.
authors.forename: Nidhi
authors.initials: N
authors.lastname: Bansal
authors.affiliation: Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, Brisbane, Queensland, Australia.
authors.forename: Lars K
authors.initials: LK
authors.lastname: Nielsen
authors.affiliation: School of Biological Sciences, Nanyang Technological University, Singapore, Singapore.
authors.forename: Zhao-Xun
authors.initials: ZX
authors.lastname: Liang
authors.affiliation: School of Agriculture and Food Sciences, University of Queensland, Brisbane, Queensland, Australia.|Queensland Alliance for Agriculture and Food Innovation, University of Queensland, Brisbane, Queensland, Australia.
authors.forename: Mark S
authors.initials: MS
authors.lastname: Turner
mesh_terms: D000249:Adenosine Monophosphate / Q000378:metabolism; D000262:Adenylyl Cyclases / Q000378:metabolism*; D001426:Bacterial Proteins / Q000378:metabolism; D002473:Cell Wall / Q000378:metabolism; D000242:Cyclic AMP / Q000378:metabolism; D015226:Dinucleoside Phosphates / Q000096:biosynthesis*; D013294:Lactococcus lactis / Q000201:enzymology / Q000378:metabolism*; D010457:Peptidoglycan / Q000096:biosynthesis / Q000378:metabolism; D010733:Phosphoglucomutase / Q000378:metabolism*; D010727:Phosphoric Diester Hydrolases / Q000378:metabolism; D019761:Phosphorus-Oxygen Lyases / Q000378:metabolism; D015290:Second Messenger Systems
chemical_list: D001426:Bacterial Proteins; D015226:Dinucleoside Phosphates; D010457:Peptidoglycan; C528998:cyclic diadenosine phosphate; D000249:Adenosine Monophosphate; D000242:Cyclic AMP; D010727:Phosphoric Diester Hydrolases; D019761:Phosphorus-Oxygen Lyases; D000262:Adenylyl Cyclases; C097631:phosphoglucosamine mutase; D010733:Phosphoglucomutase