The scaffold-protein IQGAP1 enhances and spatially restricts the actin-nucleating activity of Diaphanous-related formin 1 (DIAPH1).

The actin cytoskeleton is a dynamic array of filaments that undergoes rapid remodeling to drive many cellular processes. An essential feature of filament remodeling is the spatio-temporal regulation of actin filament nucleation. One family of actin filament nucleators, the Diaphanous-related formins, is activated by the binding of small G-proteins such as RhoA.

Force activates smooth muscle alpha-actin promoter activity through the Rho signaling pathway.

In pressure or volume overload, hypertrophic growth of the myocardium is associated with myofibroblast differentiation, a process in which cardiac fibroblasts express smooth muscle alpha-actin (SMA). The signaling mechanisms that mediate force-induced myofibroblast differentiation and SMA expression are not defined. We examined the role of the Rho-Rho-kinase pathway in force-induced SMA expression in fibroblasts using an in vitro model system that applies static tensile forces (0.

Methylglyoxal inhibits the binding step of collagen phagocytosis.

Bacterial infection-induced fibrosis affects a wide variety of tissues, including the periodontium, but the mechanisms that dysregulate matrix turnover and mediate fibrosis are not defined. Since collagen turnover by phagocytosis is an important pathway for matrix remodeling, we studied the effect of the bacterial and eukaryotic cell metabolite, methylglyoxal (MGO), on the binding step of phagocytosis by periodontal fibroblasts. Type 1 collagen was treated with various concentrations of methylglyoxal, an important glucose metabolite that modifies Arg and Lys residues.