Xinα Background Information Xinå, also known as CMYA1 ( Cardiomyopathy-associated protein 1) or XIRP1 (xin actin-binding repeat containing 1), is a 1,843 amino acid protein that functions to protect Actin filaments from depolymerization. Colocalized to the cell junction with actin stress fibers, Xinå contains 15 Xin repeats and interacts with several proteins including ∫-catenin, Filamin and VASP (vasodilator-stimulated phosphoprotein). The Xin repeats with the protein are thought to stabilize actin-based cytoskeletons and may help to crosslink microfilaments with actin networks. Xinå shares 78% similarity with its mouse counterpart and is expressed in the heart as three alternatively spliced isoforms designated A, B and C. In mice, Xinå is essential for proper heart tube formation and correct cardiac looping, suggesting that the human homolog may have similar functions.
