PARP, a 116 kDa nuclear poly (ADP-ribose) polymerase comprise a superfamily of enzymes that functionally modify histones and other nuclear proteins, thereby preventing cell death.This protein can be cleaved by many ICE-like caspases in vitro and is one of the main cleavage targets of caspase-3 in vivo. In human PARP, the cleavage occurs between Asp214 and Gly215, which separates the PARP amino-terminal DNA binding domain (24 kDa) from the carboxy-terminal catalytic domain (89 kDa). PARP helps cells to maintain their viability; cleavage of PARP facilitates cellular disassembly and serves as a marker of cells undergoing apoptosis.PARP proteins are implicated in a variety of diseases, including cancer, neurodegenerative and inflammatory disorders.
