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Lighting Up the Pathways to Caspase Activation Using Bimolecular Fluorescence Complementation
08:47

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Published on: March 5, 2018

Structural basis of caspase-7 inhibition by XIAP

J Chai1, E Shiozaki, S M Srinivasula

  • 1Department of Molecular Biology, Princeton University, Lewis Thomas Laboratory, Washington Road, Princeton, NJ 08544, USA.

Cell
|March 21, 2001
PubMed

Insights

Inhibitor of apoptosis (IAP) proteins block cell death by inhibiting caspases. This study reveals the crystal structure of XIAP peptide binding caspase-7, offering insights for designing new caspase inhibitors.

Area of Science:

  • Biochemistry
  • Structural Biology
  • Molecular Biology

Background:

  • Inhibitor of apoptosis (IAP) proteins regulate apoptosis by targeting caspases.
  • Caspase activity is crucial for programmed cell death.
  • Understanding caspase-inhibitor interactions is key for therapeutic development.

Purpose of the Study:

  • To elucidate the structural basis of caspase-7 inhibition by XIAP.
  • To investigate the role of BIR domains in caspase inhibition.
  • To provide a foundation for designing novel caspase inhibitors.

Main Methods:

  • X-ray crystallography to determine the structure of caspase-7 and XIAP peptide complex.
  • Biochemical assays to assess inhibitory activity.
  • Structural analysis of protein-protein interactions.

Main Results:

  • The crystal structure of caspase-7 complexed with an 18-residue XIAP peptide was determined at 2.45 A resolution.
  • The XIAP peptide binds to the catalytic groove of caspase-7, mimicking interactions of known inhibitors.
  • Biochemical and structural data indicate BIR domains are not essential for inhibiting caspase-3 and -7.

Conclusions:

  • The XIAP peptide interaction with caspase-7 provides a novel structural model for caspase inhibition.
  • The BIR domains are dispensable for the inhibitory function of XIAP against caspase-3 and -7.
  • This structural insight facilitates the rational design of next-generation apoptosis-modulating drugs.

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