Cytoskeleton-Associated Protein 4: Functions Beyond the Endoplasmic Reticulum in Physiology and Disease

Figure 2

DHHC2 palmitoylation of CKAP4 is necessary for APF-mediated signaling. APF is a sialoglycopeptide that inhibits cellular proliferation of bladder epithelial cells (normal and carcinoma) and is capable of binding to the transmembrane protein CKAP4 [11, 28]. The APF/CKAP4 interaction has been shown to be required for APF’s inhibition of cellular proliferation and for the alteration of specific gene expression, including E-cadherin, ZO-1, vimentin, p53, and CCN2 [11, 29]. Further, these APF-mediated changes in cellular proliferation and gene expression are regulated by DHHC2-mediated palmitoylation of CKAP4, as CKAP4 must be palmitoylated to traffic to the cell surface [22]. There is a marked increase in the nuclear abundance of CKAP4 in response to APF; however, it is not known whether APF is also present in the nucleus.