Immunolocalization of Actin Capping Protein Alpha 1 and Alpha 2 Proteins in Marine Tissues

Actin is an essential component of all cells. Actin contributes to cell shape, cell structure and cell motility. Actin\u27s growth and regulation depends upon a variety of proteins including actin capping protein (CP). CP is composed of two different proteins, an alpha and beta subunit. The alpha subunit has three different forms: alpha1, alpha2 and alpha3. In previous studies, we have determined that the different alpha forms are expressed at different levels in a variety of tissues and some tissues contain only alpha1 or only alpha2. This data suggests that the different alpha subunits may have different functions. The goal of my undergraduate research is to elucidate the cellular functions of the alpha subunits of CP by determining where the alpha proteins are in a cell or tissue using immunolocalization studies. Previously alpha1 and alpha2 specific antibodies were purified from rabbit polyclonal antisera. The antibodies were used in conjunction with a recently generated chicken anti-alpha! antibody and a mouse anti-actin antibody to assess the distribution of the alpha proteins relative to actin in a variety of murine tissues. CP alpha1 and alpha2 proteins have similar distributions in murine myocardium, co-localizing with actin at the Z-lines of sarcomeres. In skeletal muscle, both isoforms localized to the Z-line but unlike alpha1, alpha2 localized to the periphery of the myotubes. Preliminary location studies of the alpha proteins in a variety of murine tissues including, kidney, liver, spleen and lung will also be presented