Cables2 (Cdk5 and ABL1 enzyme substrate 2), also known as Ik3-2, is a 478 amino acid ubiquitously expressed protein that has a C-terminal cyclin box-containing domain, making it a member of the cyclin protein superfamily. A related protein, Cables, forms a trimolecular complex with Cdk5 and c-Abl in vivo, enhances apoptosis induced by overexpression of p53 and may be a tumor suppressor, due to its chromosomal loss of heterozygosity that is found in certain cancers. Cables2 shares 78% sequence similarity with Cables in the region of the cyclin box-containing domain and, in similar functionality, associates with Cdk3, Cdk5 and c-Abl. However, unlike its close relative, Cables2 also contains an N-terminal region that enhances not only p53-mediated cell death, but also p53-independent cell death. This characteristic suggests that the gene encoding Cables2 may also function as a tumor suppressor gene.
