Selective proteolysis of the nuclear replication factor MCM3 in apoptosis

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Examination of Proteins Bound to Nascent DNA in Mammalian Cells Using BrdU-ChIP-Slot-Western Technique
09:14

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Published on: January 14, 2016

B L Schwab1, M Leist, R Knippers

  • 1Department of Biology, University of Konstanz, Konstanz, Germany.

Experimental Cell Research
|March 14, 1998
PubMed

Insights

Specific protein cleavage drives apoptosis. Researchers found MCM3 protein is cleaved early in apoptosis, preventing DNA replication during cell death.

Area of Science:

  • Molecular Biology
  • Cell Biology
  • Biochemistry

Background:

  • Protein degradation is crucial for apoptosis execution and cell fate decisions.
  • Specific protein cleavage regulates structural changes and signaling pathways in programmed cell death.
  • The role of replicative protein complexes in apoptosis is not fully understood.

Purpose of the Study:

  • To investigate the role of MCM (minichromosome maintenance) proteins during apoptosis.
  • To determine if MCM proteins are cleaved during programmed cell death.
  • To elucidate the functional consequences of MCM protein cleavage in apoptosis.

Main Methods:

  • Induction of apoptosis in various cell models.
  • Treatment with caspase inhibitors to block apoptosis.
  • Induction of necrosis via energy deprivation.
  • Analysis of MCM protein cleavage using biochemical assays.

Main Results:

  • MCM3, a replicative protein, was found to be specifically cleaved early in apoptosis.
  • Cleavage of MCM3 was inhibited by caspase inhibitors, indicating caspase-dependent proteolysis.
  • MCM3 cleavage did not occur during necrosis induced by energy deprivation.
  • Other MCM family members were not significantly cleaved under apoptotic conditions.

Conclusions:

  • Early cleavage of MCM3 is a specific event during apoptosis, mediated by caspases.
  • This cleavage likely inactivates the MCM complex, preventing DNA replication during cell death.
  • MCM3 degradation serves as a mechanism to safeguard genome integrity during apoptosis.

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