Platelet inhibition by hypochlorous acid involves cAMP signalling.

Hypochlorous acid (HOCl), made by neutrophil-derived myeloperoxidase, has been suggested to inhibit platelets, however, the mechanisms involved have not been described. Here we confirm that HOCl exposure changes platelet morphology and inhibits platelet spreading and aggregation. HOCl effects could be reversed by glutathione suggesting a role for cysteine oxidation.

Effects of exercise on cAMP-mediated platelet inhibition in young women: a pilot study.

Purpose: Exercise has been shown to reduce platelet reactivity and increase platelet sensitivity to prostacyclin, an endothelium-derived inhibitor of platelet activation, in middle-aged men and women. It is currently unknown if these beneficial effects can also be observed in young women and the intracellular mechanisms involved have not been identified. In this study, the feasibility of detecting changes in platelet reactivity, prostacyclin sensitivity and cAMP signalling were tested.

Roles of G proteins and their GTPase-activating proteins in platelets.

Platelets are small anucleate blood cells supporting vascular function. They circulate in a quiescent state monitoring the vasculature for injuries. Platelets adhere to injury sites and can be rapidly activated to secrete granules and to form platelet/platelet aggregates.

RhoGAP6 interacts with COPI to regulate protein transport.

RhoGAP6 is the most highly expressed GTPase-activating protein (GAP) in platelets specific for RhoA. Structurally RhoGAP6 contains a central catalytic GAP domain surrounded by large, disordered N- and C-termini of unknown function. Sequence analysis revealed three conserved consecutive overlapping di-tryptophan motifs close to the RhoGAP6 C-terminus which were predicted to bind to the mu homology domain (MHD) of δ-COP, a component of the COPI vesicle complex.

Analysis of protein phosphorylation using Phos-tag gels.

Phosphorylation is a major regulatory mechanism controlling protein and cell function. Phosphoproteomics is continuing to reveal the extent and complexity of protein phosphorylation. In particular, most proteins are emerging to contain multiple phosphorylation sites.