Various human skin disorders are associated with aberrant regulation of the cytoskeleton (the scaffolding that supports the cell). This is because many physiological processes in the skin, including wound healing and hair follicle cycling, involve cytoskeleton reorganization regulated by the proteins Cdc42 and Rac1.
A team of researchers, led by Scott Snapper, at Massachusetts General Hospital, Boston, has now determined that the protein N-WASP, which acts downstream of Cdc42 to regulate cytoskeleton reorganization, has a key role in skin function and hair follicle cycling by generating and analyzing mice lacking N-WASP in skin.
Analysis of the mice indicated that N-WASP is critical for cells of the outer layer of the skin to proliferate and for hair growth but is dispensable for wound healing. The role of N-WASP in hair growth was found to be a result of its key role in hair follicle cycling and in the maintenance and differentiation of hair follicle progenitor cells. As further analysis indicated that N-WASP regulated the function of the gene regulatory protein ß-catenin in cells of the outer layer of the skin from hair follicles, the authors suggest that N-WASP promotes ß-catenin-dependent gene expression, thereby supporting the differentiation of hair follicle progenitor cells.