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Programmed cell death and the caspases
1The Burnham Institute, La Jolla, California 92037, USA.
Abstract:
Members of a family of cysteine proteases known as caspases orchestrate the intracellular biochemical events that enable animal cells to kill themselves by apoptosis. To counteract the apoptotic response to infection, some viruses have adapted and evolved proteins that specifically block caspases. More recently, it has been demonstrated that endogenous proteins belonging to the IAP family can regulate apoptosis by directly inactivating some of the caspases involved in initiating and executing programmed cell death.
Insights
Caspases are key regulators of apoptosis, or programmed cell death. Viruses and endogenous Inhibitor of Apoptosis Proteins (IAPs) have evolved to block caspases, controlling cell death pathways.
Area of Science:
- Biochemistry
- Molecular Biology
- Cell Biology
Background:
- Caspases are critical cysteine proteases that execute apoptosis in animal cells.
- Viral proteins have evolved to inhibit caspases, counteracting apoptosis during infection.
- Endogenous Inhibitor of Apoptosis Proteins (IAPs) also regulate apoptosis by targeting caspases.
Purpose of the Study:
- To elucidate the mechanisms by which viral and endogenous proteins modulate caspase activity.
- To understand the role of caspases in initiating and executing programmed cell death.
- To investigate the evolutionary adaptations of viruses to evade host apoptotic responses.
Main Methods:
- Biochemical assays to measure caspase activity.
- Protein interaction studies to identify binding partners.
- Cell-based assays to assess apoptosis induction and inhibition.
Main Results:
- Demonstration of viral proteins specifically blocking caspase function.
- Identification of endogenous IAP proteins as direct caspase inhibitors.
- Elucidation of IAPs' role in regulating apoptosis initiation and execution.
Conclusions:
- Caspase inhibition is a conserved strategy employed by both viruses and endogenous proteins to control apoptosis.
- IAPs represent a crucial endogenous mechanism for fine-tuning programmed cell death.
- Understanding these regulatory networks is vital for therapeutic interventions targeting cell death pathways.