The p33ING1 protein encodes a 33-kD, 294-amino acid protein that displays the characteristics of a tumor suppressor gene. The p33ING1 protein is a regulator of cell cycle, senescence, and apoptosis. It can mediate growth arrest, anchor dependent growth and influence chemo sensitivity (1-4). It also has a proposed role as a growth regulator, which is consistent with its location in the nucleus (5).
It has been demonstrated that the ING1 gene has three exons and that four mRNA variants are transcribed from three different promoter regions (p33 ING1, p24 ING1, p27 ING1, p47 IG1) (6, 7). ING1 can possibly influence the above biological functions depending on which variant is expressed (1-4).