The effector caspases drICE and dcp-1 have partially overlapping functions in the apoptotic pathway in Drosophila

• DOI: 10.1038/sj.cdd.4401920
• Publication Date: 2006-04-28T10:39:27Z
• Authors: D Xu; Y Wang; R Willecke; Z Chen; T Ding; A Bergmann
• Keywords: Inhibitor of apoptosis

Caspases are essential components of the apoptotic machinery in both vertebrates and invertebrates. Here, we report the isolation of a mutant allele of the Drosophila effector caspase drICE as a strong suppressor of hid- (head involution defective-) induced apoptosis. This mutant was used to determine the apoptotic role of drICE. Our data are consistent with an important function of drICE for developmental and irradiation-induced cell death. Epistatic analysis suggests that drICE acts genetically downstream of Drosophila inhibitor of apoptosis protein 1 (Diap1). However, although cell death is significantly reduced in drICE mutants in all assays, it is not completely blocked. A double-mutant analysis between drICE and death caspase-1 (dcp-1), another effector caspase, reveals that some cells (type I) strictly require drICE for apoptosis, whereas other cells (type II) require either drICE or dcp-1. Thus, these data demonstrate a barely appreciated complexity in the apoptotic pathway, and are consistent with current models about effector caspase regulation in both vertebrates and invertebrates.