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Understanding CARD Tricks in Apoptosomes

Li Wang1, Qi Qiao1, Hao Wu1

  • 1Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, and Program in Cellular and Molecular Medicine, Boston Children's Hospital, Boston, MA 02115, USA.

Structure (London, England : 1993)
|April 6, 2017
PubMed

Insights

Researchers resolved the Apaf-1 CARD and caspase-9 CARD complex structure. This structural insight advances understanding of the holo-apoptosome, crucial for programmed cell death.

Area of Science:

  • Biochemistry
  • Molecular Biology
  • Structural Biology

Background:

  • The apoptosome is a large protein complex that initiates apoptosis.
  • Apaf-1 forms a heptameric wheel, but the central caspase-9 recruitment domain (CARD) structure was unclear.

Purpose of the Study:

  • To elucidate the structural basis of caspase-9 recruitment by Apaf-1.
  • To provide a more complete picture of the holo-apoptosome.

Main Methods:

  • X-ray crystallography of the Apaf-1 CARD and caspase-9 CARD complex.
  • Integration of cryo-electron microscopy (cryo-EM) data.

Main Results:

  • A high-resolution crystal structure of the Apaf-1 CARD-caspase-9 CARD complex was determined.
  • This structure reveals the molecular interactions mediating caspase-9 recruitment.

Conclusions:

  • The resolved structure clarifies the architecture of the apoptosome's central hub.
  • This work contributes significantly to understanding the mechanism of apoptosis initiation.

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