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pubmed:abstractText |
Cell death in higher organisms is negatively regulated by Inhibitor of Apoptosis Proteins (IAPs), which contain a ubiquitin ligase motif, but how ubiquitin-mediated protein degradation is regulated during apoptosis is poorly understood. Here, we report that Drosophila melanogaster IAP1 (DIAP1) auto-ubiquitination and degradation is actively regulated by Reaper (Rpr) and UBCD1. We show that Rpr, but not Hid (head involution defective), promotes significant DIAP1 degradation. Rpr-mediated DIAP1 degradation requires an intact DIAP1 RING domain. Among the mutations affecting ubiquitination, we found ubcD1, which suppresses rpr-induced apoptosis. UBCD1 and Rpr specifically bind to DIAP1 and stimulate DIAP1 auto-ubiquitination in vitro. Our results identify a novel function of Rpr in stimulating DIAP1 auto-ubiquitination through UBCD1, thereby promoting its degradation.
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pubmed:affiliation |
Howard Hughes Medical Institute, Strang Laboratory of Cancer Research, The Rockefeller University Box 252, 1230 York Ave. New York, NY 10021, USA.
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pubmed:publicationType |
Journal Article,
In Vitro,
Research Support, U.S. Gov't, P.H.S.,
Research Support, Non-U.S. Gov't
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