In vertebrates, intercellular communication via gap junctions is mediated by the connexin family of molecules, which is made up of at least 13 members. These proteins, which have four transmembrane domains and intracellular C- and N-termini, oligomerize to form hemichannels. Oligomers in the adjacent membranes of two closely apposed cells 'dock' to form intercellular channels, through which ions and small molecules move.
FEMS Microbiol Lett,
Staphylococcus lugdunensis is a human skin commensal organism, but it is considered as a virulent Staphylococcus species. In a previous study, we described the first S.lugdunensis autolysin, AtlL. This enzyme displays two enzymatic domains and generates two peptidoglycan hydrolases, an N-acetylmuramoyl-l-alanine amidase and an N-acetylglucosaminidase. In this study, to further investigate the functions of this autolysin, a atlL mutant was constructed. The microscopic examination of the mutant showed cell aggregates and revealed a rough outer cell surface demonstrating, respectively, the roles of AtlL in cell separation and peptidoglycan turnover. This atlL mutant exhibited a lower susceptibility to Triton X-100-induced autolysis assays and appears to be more resistant to cell wall antibiotic-induced lysis and death compared with its parental strain. The atlL mutation affected the biofilm formation capacity of S.lugdunensis. Furthermore, the atlL mutant showed trends toward reduced virulence using the Caenorhabditis elegans model. Overall, AtlL appears as a major cell wall autolysin of S.lugdunensis implicated in cell separation, in stress-induced autolysis and in bacterial pathogenesis.