On the Interaction Between Human IQGAP1 and Actin.

IQGAPs are eukaryotic proteins which integrate signals from various sources and pass these on the cytoskeleton. Understanding how they do this requires information on the interfaces between the proteins. Here, it is shown that the calponin homology domain of human IQGAP1 (CHD1) can be crosslinked with α-actin.

The Vibrio cholerae trh gene is coordinately regulated in vitro with type III secretion system genes by VttR(A)/VttR(B) but does not contribute to Caco2-BBE cell cytotoxicity.

Numerous virulence factors have been associated with pathogenic non-O1/non-O139 serogroup strains of Vibrio cholerae. Among them are the thermostable direct hemolysin (TDH) and the TDH-related hemolysin (TRH), which share amino acid similarities to the TDH and TRH proteins of Vibrio parahaemolyticus, where they have been shown to contribute to pathogenesis. Although TDH and TRH homologs can be encoded on extrachromosomal elements in V.

A calcium-dependent interaction between calmodulin and the calponin homology domain of human IQGAP1.

IQGAPs are cytoskeletal scaffolding proteins which collect information from a variety of signalling pathways and pass it on to the microfilaments and microtubules. There is a well-characterised interaction between IQGAP and calmodulin through a series of IQ-motifs towards the middle of the primary sequence. However, it has been shown previously that the calponin homology domain (CHD), located at the N-terminus of the protein, can also interact weakly with calmodulin.

The interaction of IQGAPs with calmodulin-like proteins.

Since their identification over 15 years ago, the IQGAP (IQ-motif-containing GTPase-activating protein) family of proteins have been implicated in a wide range of cellular processes, including cytoskeletal reorganization, cell-cell adhesion, cytokinesis and apoptosis. These processes rely on protein-protein interactions, and understanding these (and how they influence one another) is critical in determining how the IQGAPs function. A key group of interactions is with calmodulin and the structurally related proteins myosin essential light chain and S100B.

IQ-motif selectivity in human IQGAP2 and IQGAP3: binding of calmodulin and myosin essential light chain.

The IQGAP [IQ-motif-containing GAP (GTPase-activating protein)] family members are eukaryotic proteins that act at the interface between cellular signalling and the cytoskeleton. As such they collect numerous inputs from a variety of signalling pathways. A key binding partner is the calcium-sensing protein CaM (calmodulin).

vttRA and vttRB Encode ToxR family proteins that mediate bile-induced expression of type three secretion system genes in a non-O1/non-O139 Vibrio cholerae strain.

Strain AM-19226 is a pathogenic non-O1/non-O139 serogroup Vibrio cholerae strain that does not encode the toxin-coregulated pilus or cholera toxin but instead causes disease using a type three secretion system (T3SS). Two genes within the T3SS pathogenicity island, herein named vttR(A) (locus tag A33_1664) and vttR(B) (locus tag A33_1675), are predicted to encode proteins that show similarity to the transcriptional regulator ToxR, which is found in all strains of V. cholerae.

The long-term environmental behaviour of strontium and barium released from former mine workings in the granites of the Sunart region of Scotland, UK.

The concentrations of strontium and barium have been measured in water, sediment and the shells of mussels (Mytilus edulis) from a river system in the Sunart region of Scotland, UK. The aim was to establish the fate and mobility of these elements, which are slowly being released from old mine workings on the Strontian granites. Enhanced strontium (1500-2000 microg l(-1) and 250-290 microg l(-1)) and barium concentrations (316 microg l(-1) and 83 microg l(-1)) were found in the waters originating from the two mine drains studied.