ASPP proteins (ASPP1, ASPP2 and iASPP) represent a new family of p53 binding proteins. ASPP1 and ASPP2 bind and enhance p53-mediated apoptosis. In contrast, the third member, iASPP, functionally inactivates p53. iASPP (also called protein phosphatase 1 regulatory (inhibitor) subunit 13 like protein, Inhibitor of ASPP protein, Protein iASPP, PPP1R13B-like protein and NFkB-interacting protein 1) plays a central role in regulation of apoptosis and transcription via its interaction with NF-kappa-B and p53/TP53 proteins. iASPP blocks transcription of HIV-1 virus by inhibiting the action of both NF-kappa-B and SP1.
This affinity purified antibody was prepared from whole rabbit serum produced by repeated immunizations with a synthetic peptide corresponding to amino acids 780-797 of human iASPP (isoform 1) protein.