Cleavage of Shigella surface protein VirG occurs at a specific site, but the secretion is not essential for intracellular spreading

Regulation of surface presentation of IcsA, a Shigella protein essential to intracellular movement and spread, is growth phase dependent.

After lysing the phagocytic vacuole, Shigella spp. accumulate filaments of polymerized actin on their surface at one pole, leading to the formation of actin tails that enable them to move through the cytoplasm. We have recently demonstrated that the Shigella protein IcsA is located at the pole that is adjacent to the growing end of the actin tail (M. B. Goldberg, O. Barzu, C. Parsot, and P. J. ...

Engineered and construction of pDS132::∆virG as suicide vector for targeted gene deletion of virG from Shigella flexneri 2a in order to generation a live attenuated Shigella vaccine

Background & Objective: Shigella are Gram negative bacteria capable of inducing their entry into non-phagocytic cells via secretion of various effector proteins called invasion plasmid antigens (Ipas). The most important of them is VirG protein. Live attenuated Shigella vaccines have indicated promise in inducing protective immune responses in human clinical trials. In current situation, const...

Shigella flexneri LuxS quorum-sensing system modulates virB expression but is not essential for virulence.

Quorum-sensing systems regulate the expression of virulence factors in a wide variety of plant and animal pathogens, including members of the Enterobacteriaceae. Studies of Shigella virulence gene expression have demonstrated that maximal expression of genes encoding the type III secretion system and its substrates and maximal activity of this virulence organelle occur at high cell density. In ...

Transgenic Mice ZP3 into the Extracellular Egg Coat of Essential for Secretion and Integration of Conserved Furin Cleavage Site Not

Cytomegalovirus assemblin (pUL80a): cleavage at internal site not essential for virus growth; proteinase absent from virions.

The human cytomegalovirus (HCMV) maturational proteinase is synthesized as an enzymatically active 74-kDa precursor that cleaves itself at four sites. Two of these, called the maturational (M) and release (R) sites, are conserved in the homologs of all herpesviruses. The other two, called the internal (I) and cryptic (C) sites, have recognized consensus sequences only among cytomegalovirus (CMV...