High impact information on Ice

• A significant proportion of cellular DRONC and DRICE appears to localize near mitochondria, suggesting that an apoptosome may form in the vicinity of mitochondria in the absence of cytochrome c release [1].
• drICE is an essential caspase required for apoptotic activity in Drosophila cells [2].
• Induction of apoptosis by rpr overexpression or by cycloheximide or etoposide treatment of Drosophila cells results in proteolytic processing of drICE [3].
• We show that overexpression of drICE sensitizes Drosophila cells to apoptotic stimuli and that expression of an N-terminally truncated form of drICE rapidly induces apoptosis in Drosophila cells [3].
• On the other hand, expression of either full-length drICE (fl-drICE) or truncated drICE (DeltaN-drICE) in the retina showed no obvious eye phenotype [4].

Biological context of Ice

• These observations demonstrate that Ice plays an important non-redundant role as a cell death effector [5].
• Animals lacking Ice show a number of defects in cell death, including those that occur during embryonic development, as well as during formation of adult eyes, arista and wings [5].
• Epistatic analysis suggests that drICE acts genetically downstream of Drosophila inhibitor of apoptosis protein 1 (Diap1) [6].
• Using RNA interference in an ecdysone-responsive Drosophila cell line, we show that drice up-regulation is essential for apoptosis induced by ecdysone [7].
• We noted a difference in the effects of silencing the executioner caspases DCP-1 and DRICE; knock-down of either or both of these had dramatic effects to sustain cell survival following depletion of DIAP1, but had only minor effects following cellular stress [8].

Anatomical context of Ice

• Finally, we demonstrate that Ice participates in, but is not absolutely required for, the non-apoptotic process of spermatid differentiation [5].

Associations of Ice with chemical compounds

• DRONC autoprocesses itself following a glutamate residue, but processes a second caspase, drICE, following an aspartate [9].

Physical interactions of Ice

• Consistently, we show that DIAP2 binds active drICE [10].

Enzymatic interactions of Ice

• Although active DCP-1 protein cleaves full-length DCP-1 and full-length drICE in vitro, GMR-DeltaN-dcp-1 did not enhance the eye phenotype of GMR-fl-dcp-1 or GMR-fl-drICE flies [4].

Regulatory relationships of Ice

• We also show that drice expression is specifically controlled by the ecdysone-regulated transcription factor BR-C [7].
• We conclude that D-IAP1 is capable of inhibiting the activation of drICE as well as inhibiting apoptosis induced by the active form of drICE [11].

Other interactions of Ice

• In Drosophila, the APAF-1 homolog ARK is required for the activation of the initiator caspase DRONC, which in turn cleaves the effector caspases DRICE and DCP-1 [8].

References