Figure 1.

cIAP2 compensates for cIAP1 and XIAP deficiency in vivo

(A) Reverse-transcription PCR (RT–PCR) demonstrating the absence of mRNA transcript in primary MEFs generated from IAP null mice. (B) Immunoblot demonstrating the upregulation of cIAP2 in various xiap^−/−ciap1^−/− tissues. cIAP1 and cIAP2 protein were detected using a pan-cIAP antibody (RIAP1). (C, D) Western blot (C) and RT–PCR (D) of protein lysates and mRNA collected from MEFs incubated with or without 10 ng/ml recombinant mTNFα for the indicated times. (E, F) Comparison of IAP mRNA transcripts (E) and protein expression (F) in unstimulated MEFs derived from mice generated by classical (ciap1^−/−, ciap2^−/−) and conditional (ciap1^lox/loxciap2^FRT/FRT, ciap1^−/−ciap2^FRT/FRT, ciap1^−/−ciap2^−/−) knockout approaches. (G) MEFs were treated with proteasomal inhibitor epoxomicin (0.5 μM) for 6 h and harvested for protein detection by Western blot.