Polyclonal Antibody to cIAP1

Background
cIAP1 (HIAP2, MIHB)  is a member of the family of inhibitor of apoptosis proteins (IAP).  IAPs suppress mitochondria-dependent and -independent apoptosis by binding to and inhibiting caspases through their BIR domains (reviewed in Liston et al, 2003; Wright and Duckett, 2005).  Resistance towards apoptosis is a hallmark of cancer cells, and overexpression of IAPs can contribute to the development of cancer though inhibiting apoptosis.  In addition to at least one BIR domain, some IAP members also have a RING-type finger motif at their carboxyl-terminal.  The RING finger domain of several IAPs, including cIAP2, have E3 ubiquitin ligase activity and target the degradation of Smac/DIABLO through ubqiuitination.  Smac/DIABLO is a death inducer and functions by inhibiting IAP-caspase interactions, thereby promoting apoptosis.  Degradation of cell death inducers like Smac/DIABLO is thought to be a conserved mechanism by which IAPs  enhance their anti-apoptotic activity, thereby promoting cell survival.   The IAPs, including cIAP1, have widespread tissue protein expression, with expression levels and subcellular localization patterns differing depending on the cell lineage (see Vischioni et al. 2005 for a comprehensive study).   IMG-5715 recognizes cIAP1,  human cIAP1 is a 618 amino acid protein. 

Antigen
A synthetic peptide corresponding to amino acids 158-175 (PNPLNSRAVEDISSSRTN) of human cIAP1 was used as immunogen, GenBank no.   gi|2497238.

Application Notes
1. cIAP1 has 618 amino acids according to GenBank no. gi|2497238 and migrates at ~70 kDa on SDS-PAGE.   2. Observed molecular weights may vary as genes generally produce, by alternative splicing, multiple transcripts all with introns, putatively encoding multiple different protein isoforms. Additionally, proteins may undergo post translational modifications including phosphorylation, glycosylation and cleavage which can result in differential molecular weights.  Protein modifications can vary between cell and tissue type, and proteins can migrate as one or multiple bands depending on the isoform expressed as well as post-translational modifications.  Users are encourage to refer to the NCBI AceView (http://www.ncbi.nlm.nih.gov/IEB/Research/Acembly/) and BLAST (http://www.ncbi.nlm.nih.gov/BLAST/) data bases for more information.

Reference
1. Wright CW and CS Duckett. 2005. Reawakening the cellular death program in neoplasia through the therapeutic blockade of IAP function. J Clin Investigation. 115:2673-2678.
2. Liston P, WG Fong and RG Korneluk. 2003. The inhibitors of apoptosis: there is more to life than Bcl2. Oncogene. 22:8568-8580.
3. Vischioni B, P van der Valk, SWS Ing, FAE Kruyt, JA Rodriguez, and G Giaccone. 2006. Expression and localization of inhibitor of apoptosis proteins in normal human tissues. Human Pathology. 37:78-86.