Coiled Coil Domain Containing Protein 6 (CCDC6)

PTC, is a novel, rearranged form of the RET protooncogene fused to a then-unknown nucleotide sequence, which they called H4.PTC1 oncoprotein forms a dimer in vivo, and the leucine zipper in the N-terminal region of H4 is responsible for this dimerization. Dimerization is essential for tyrosine hyperphosphorylation and the transforming activity of the PTC1 oncogene.ATM-deficient lymphoblasts showed cytoplasmic H4 localization, and ionizing radiation failed to induce H4 thr434 phosphorylation. Inhibition of ATM interfered with H4 apoptotic activity, and expression of H4 with a thr434-to-ala mutation protected cells from genotoxic stress-induced apoptosis. Furthermore, silencing of H4 increased cell survival and allowed DNA synthesis and mitotic progression in irradiated human cell lines.