Analyzing the role of CagV, a VirB8 homolog of the type IV secretion system of Helicobacter pylori. Issue 7 (24th May 2017) - Kumar, Navin
Abstract : Little is known about the architecture of the multicomponent type IV secretion system of Helicobacter pylori (Cag‐T4SS). In this study, we investigated the interactions of the component CagV, which forms a homodimer in the inner membrane. The stability of CagV is independent of other Cag components, but its absence partially affects the level of CagI, a protein involved in pilus formation. It interacts with a number of Cag components and is essential for the surface localization of substrate CagA, but not that of CagT and CagX. Abstract : The type IV secretion system of Helicobacter pylori (Cag‐T4SS) is composed of ~ 27 components including a VirB8 homolog, CagV. We have characterized CagV and reported that it is an inner membrane protein and, like VirB8, forms a homodimer. Its stability is not dependent on the other Cag components and the absence of cagV affects the stability of only CagI, a protein involved in pilus formation. CagV is not required for the stability and localization of outer membrane subcomplex proteins, but interacts with them through CagX. It also interacts with the inner membrane‐associated components, CagF and CagZ, and is required for the surface localization of CagA. The results of this study might help in deciphering the mechanistic contributions of CagV in the Cag‐T4SS biogenesis and function.