Inhibitor of growth (ING) domain of inhibitor of growth protein 3 (ING3), Yng2p and similar proteins
ING3, also termed p47ING3, is a member of the inhibitor of growth (ING) family of type II tumor suppressors. It is ubiquitously expressed and has been implicated in transcription modulation, cell cycle control, and the induction of apoptosis. It is an important subunit of human NuA4 histone acetyltransferase complex, which regulates the acetylation of histones H2A and H4. Moreover, ING3 promotes ultraviolet (UV)-induced apoptosis through the Fas/caspase-8-dependent pathway in melanoma cells. It physically interacts with subunits of E3 ligase Skp1-Cullin-F-boxprotein complex (SCF complex) and is degraded by the SCF (F-box protein S-phase kinase-associated protein 2, Skp2)-mediated ubiquitin-proteasome system. It also acts as a suppression factor during tumorigenesis and progression of hepatocellular carcinoma (HCC). Yeast chromatin modification-related protein Yng2p, also termed ESA1-associated factor 4 or ING1 homolog 2, is a subunit of the NuA4 histone acetyltransferase (HAT) complex. It plays a critical role in intra-S-phase DNA damage response. Members of this family contain an N-terminal leucine zipper-like (LZL) motif-containing ING domain, and a well-characterized C-terminal plant homeodomain (PHD)-type zinc-finger domain.