The Drosophila Caspase DRONC Cleaves following Glutamate or Aspartate and Is Regulated by DIAP1, HID, and GRIM

doi:10.1074/jbc.M000869200

The Drosophila Caspase DRONC Cleaves following Glutamate or Aspartate and Is Regulated by DIAP1, HID, and GRIM*

From the Division of Biology, MC 156-29, Pasadena, California 91125

Abstract

The caspase family of cysteine proteases plays important roles in bringing about apoptotic cell death. All caspases studied to date cleave substrates COOH-terminal to an aspartate. Here we show that the Drosophila caspase DRONC cleaves COOH-terminal to glutamate as well as aspartate. DRONC autoprocesses itself following a glutamate residue, but processes a second caspase, drICE, following an aspartate. DRONC prefers tetrapeptide substrates in which aliphatic amino acids are present at the P2 position, and the P1 residue can be either aspartate or glutamate. Expression of a dominant negative form of DRONC blocks cell death induced by theDrosophila cell death activators reaper,hid, and grim, and DRONC overexpression in flies promotes cell death. Furthermore, the Drosophila cell death inhibitor DIAP1 inhibits DRONC activity in yeast, and DIAP1's ability to inhibit DRONC-dependent yeast cell death is suppressed by HID and GRIM. These observations suggest that DRONC acts to promote cell death. However, DRONC activity is not suppressed by the caspase inhibitor and cell death suppressor baculovirus p35. We discuss possible models for DRONC function as a cell death inhibitor.

Footnotes

↵* This work was supported in part by grants from the Burroughs Wellcome Fund (New Investigator awards in the Pharmacological Sciences), the Ellison Medical Foundation, and National Institutes of Health Grant GM057422-01 (to B. A. H.).The costs of publication of this article were defrayed in part by the payment of page charges. The article must therefore be hereby marked “advertisement” in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.
↵‡ Contributed equally to the results of this work.
↵§ Supported by a Human Frontiers postdoctoral fellowship. Current address: Dept. of Haematology and Oncology, Royal Children's Hospital, Flemington Road, Parkville, VIC 3052, Australia.
↵¶ Supported by a Jane Coffin Child postdoctoral fellowship.
↵‖ Current address: Dept. of Enzymology, Merck Research Laboratories, Rahway, NJ 07065.
↵** Searle Scholar. To whom correspondence should be addressed. Tel.: 626-395-3399: Fax: 626-449-0756; E-mail: haybruce@its. caltech.edu.
Published, JBC Papers in Press, May 23, 2000, DOI 10.1074/jbc.M000869200
↵2 S. J. Yoo and C. J. Hawkins, unpublished data.
↵3 C. J. Hawkins and S. J. Yoo, unpublished observations.
Abbreviations:

PAGE

polyacrylamide gel electrophoresis

PARP

poly(ADP-ribosyl)transferase
- Received January 31, 2000.
- Revision received May 15, 2000.
The American Society for Biochemistry and Molecular Biology, Inc.