The primary effector for Shigella invasion of epithelial cells is IpaC, which is secreted via a type III secretion system. We recently reported that the IpaC N terminus is required for type III secretion and possibly other functions. In this study, mutagenesis was used to identify an N-terminal secretion signal and to determine the functional importance of the rest of the IpaC N terminus. The 1...

We have recently described a multicomponent cascade that regulates type III secretion in Bordetella. This cascade includes a group of proteins, BtrU, BtrW, and BtrV, that contain an array of domains that define partner-switching complexes previously characterized in gram-positive bacteria. BtrU contains a PP2C-like serine phosphatase domain, BtrW contains a serine kinase/anti-sigma factor motif...

The co-evolutionary relationship between pathogen and host has led to a regulatory cycle between virulence factors needed for survival and antivirulence factors required for host transmission. This is exemplified in Salmonella spp. by the zirTS antivirulence genes: a secretion pathway comprised of the outer membrane transporter ZirT, and its secreted partner, ZirS. ZirTS act within the gastroin...

The heat-stable enterotoxin (ST) produced by enterotoxigenic Escherichia coli is an extracellular peptide toxin that evokes watery diarrhea in the host. Two types of STs, STI and STII, have been found. Both STs are synthesized as precursor proteins and are then converted to the active forms with intramolecular disulfide bonds after being released into the periplasm. The active STs are finally t...

expression of eukaryotic proteins in e. coli often results in their aggregation. proper folding and solubility of therapeutical proteins are the pre-requisite for their bioactivity. this is not achieved in cytoplasmic expression in e. coli because of the absence of disulfide bonds formation. a novel expression/secretion vector was constructed which exploited β-lactamase signal sequence to trans...

Advocacy intervention has been shown to be efficacious at reducing depressive symptoms in women who suffer from intimate partner violence (IPV). However, the intervention effect among abused immigrant women has not been well studied. This study compares the demographic and psychosocial characteristics between abused immigrant and nonimmigrant women, and evaluates the impact of immigration statu...

Oxytocin is thought to play a central role in promoting close social bonds via influence on social interactions. The current investigation targeted interactions involving expressed gratitude between members of romantic relationships because recent evidence suggests gratitude and its expression provides behavioral and psychological 'glue' to bind individuals closer together. Specifically, we too...

The type VI secretion systems (T6SS) are present in about a quarter of all Gram-negative bacteria. Several key components of T6SS are evolutionarily related to components of contractile nanomachines such as phages and R-type pyocins. The T6SS assembly is initiated by formation of a membrane complex that binds a phage-like baseplate with a sharp spike, and this is followed by polymerization of a...

Background: Equine follicle stimulating hormone (eFSH) is a pituitary heterodimeric glycoprotein consists of noncovalently linked of generic alpha subunit and a hormone specific beta subunit. The molecular weights of the subunits are similar and about 16 KD. In general, FSH plays a key role in controlling vertebrate gonadal functions. In female mammals, ovarian maturation and follicular growth ...