Human CKAP4/p63 Antibody

CKAP4 (Cytoskeleton-associated protein 4; also CLIMP63 and p63) is a 63-64 kDa molecule that belongs to no known protein family. It is found intracellularly, and on the plasma membrane of select cells such as vascular smooth muscle and Type II Greater alveolar lung cells. CKAP4 has a bimodal distribution. First, it is embedded in the membrane of a compartment that links the ER with the Golgi apparatus. This localization is dependent upon its ability to form homooligomers, and its presence serves to anchor microtubules and direct the formation of tubular ER. Second, it is embedded in the plasma membrane and serves as a receptor for SP-A/surfactant protein-A (in lung) and tPA (in vessels). Human CKAP4 is a 602 amino acid (aa) type II transmembrane nonglycosylated protein. It contains a 106 aa N-terminal cytoplasmic region plus a 475 aa C-terminal luminal domain (aa 128-602). The luminal domain contains three coiled-coil regions (aa 130-214; 256-460; 533-602) plus three utilized phosphorylation sites. CKAP4 undergoes reversible palmitoylation. There are two potential isoform variants. One contains an alternative start at Met269, while another shows a deletion of aa 258-435. Over aa 128-602, human CKAP4 shares 82% aa sequence identity with mouse CKAP4.