However, recent computational analysis involving data integration methods of machine-learning
techniques to train on sets of known T3SS effectors has revealed that the amino-terminal secretion signal of T3SS effectors could be taxonomically universal and conserved in animal and plant pathogens (Arnold et al., 2009; Lower & Schneider, 2009; Samudrala et al., 2009; Yang et al., 2010). This finding implies that the amino-terminal secretion signal could be interchangeable between T3SS effectors originating from different bacteria. The amino-terminal secretion signal itself may interact with ATPases in any T3SSs (Sorg et al., 2006) or with other T3SS components for efficient secretion. In other words, T3SS-associated chaperones alone may be the determinant for specific secretion in certain cases. Based on this NVP-AUY922 hypothesis, the mechanism of the specificity of T3SS1 or 2 effector secretion should be tested by the specific interaction of their cognate chaperones (VepA and VocC) and other T3SS1 or two components, such as T3SS-associated
ATPase (Akeda & Galán, 2005) or the recently identified secretion-sorting platform in Salmonella, SpaO-OrgA-OrgB (Lara-Tejero et al., 2011), which are known to interact with T3SS effector–chaperone complexes. These experiments would clarify which molecules determine the specificity of T3SS effector secretion in V. parahaemolyticus. This work was supported by Grants-in-Aid for Young Ulixertinib research buy Scientists and Scientific Research in Priority Areas from the Ministry of Education, Culture, Sports, Science and Technology of Japan and from the Takeda Science Foundation. “
“Azospirillum brasilense is a rhizobacterium that provides Thymidine kinase beneficial effects on plants when they colonize roots. The formation of complex bacterial communities known as biofilms begins with the interaction of planktonic cells with surfaces in response to appropriate signals. Nitric oxide (NO) is a signaling molecule implicated
in numerous processes in bacteria, including biofilm formation or dispersion, depending on genera and lifestyle. Azospirillum brasilense Sp245 produces NO by denitrification having a role in root growth promotion. We analyzed the role of endogenously produced NO on biofilm formation in A. brasilense Sp245 and in a periplasmic nitrate reductase mutant (napA::Tn5; Faj164) affected in NO production. Cells were statically grown in media with nitrate or ammonium as nitrogen sources and examined for biofilm formation using crystal violet and by confocal laser microscopy. Both strains formed biofilms, but the mutant produced less than half compared with the wild type in nitrate medium showing impaired nitrite production in this condition. NO measurements in biofilm confirmed lower values in the mutant strain.