Identification of a Variant Form of Cellular Inhibitor of Apoptosis Protein (c-IAP2) That Contains a Disrupted Ring Domain

  • Park, Sun-Mi (Department of Biology and Protein Network Research Center, Yonsei University) ;
  • Kim, Ji-Su (Department of Biology and Protein Network Research Center, Yonsei University) ;
  • Park, Ji-Hyun (Department of Biology and Protein Network Research Center, Yonsei University) ;
  • Kang, Seung-Goo (Department of Biology and Protein Network Research Center, Yonsei University) ;
  • Lee, Tae Ho (Department of Biology and Protein Network Research Center, Yonsei University)
  • Published : 2002.09.30

Abstract

Among the members of the inhibitor of apoptosis (IAP) protein family, only Livin and survivin have been reported to have variant forms. We have found a variant form of c-IAP2 through the interaction with the X protein of HBV using the yeast two-hybrid system. In contrast to the wild-type c-IAP2, the variant form has two stretches of sequence in the RING domain that are repeated in the C-terminus that would disrupt the RING domain. We demonstrate that the variant form has an inhibitory effect on TNF-mediated $NF-{\kappa}B$ activation unlike the wild-type c-IAP2, which increases TNFmediated $NF-{\kappa}B$ activation. These results suggest that this variant form has different activities from the wild-type and the RING domain may be involved in the regulation of TNF-induced $NF-{\kappa}B$ activation.

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