The Apaf-1 apoptosome induces formation of caspase-9 homo- and heterodimers with distinct activities

Chu Chiao Wu, Sunhee Lee, Srinivas Malladi, Miao Der Chen, Nicholas J. Mastrandrea, Zhiwen Zhang, Shawn B. Bratton

Research output: Contribution to journalArticle

21 Citations (Scopus)

Abstract

According to dogma, initiator caspases are activated through proximity-induced homodimerization, but some studies infer that during apoptosis caspase-9 may instead form a holoenzyme with the Apaf-1 apoptosome. Using several biochemical approaches, including a novel site-specific crosslinking technique, we provide the first direct evidence that procaspase-9 homodimerizes within the apoptosome, markedly increasing its avidity for the complex and inducing selective intramolecular cleavage at Asp-315. Remarkably, however, procaspase-9 could also bind via its small subunit to the NOD domain in Apaf-1, resulting in the formation of a heterodimer that more efficiently activated procaspase-3. Following cleavage, the intersubunit linker (and associated conformational changes) in caspase-9-p35/p12 inhibited its ability to form homo- and heterodimers, but feedback cleavage by caspase-3 at Asp-330 removed the linker entirely and partially restored activity to caspase-9-p35/p10. Thus, the apoptosome mediates the formation of caspase-9 homo- and heterodimers, both of which are impacted by cleavage and contribute to its overall function.

Original languageEnglish (US)
Article number13565
JournalNature Communications
Volume7
DOIs
StatePublished - Nov 24 2016

Fingerprint

Apoptosomes
Caspase 9
cleavage
Caspase 3
apoptosis
crosslinking
initiators
Initiator Caspases
proximity
Holoenzymes
Crosslinking
Apoptosis
Feedback

ASJC Scopus subject areas

  • Chemistry(all)
  • Biochemistry, Genetics and Molecular Biology(all)
  • Physics and Astronomy(all)

Cite this

The Apaf-1 apoptosome induces formation of caspase-9 homo- and heterodimers with distinct activities. / Wu, Chu Chiao; Lee, Sunhee; Malladi, Srinivas; Chen, Miao Der; Mastrandrea, Nicholas J.; Zhang, Zhiwen; Bratton, Shawn B.

In: Nature Communications, Vol. 7, 13565, 24.11.2016.

Research output: Contribution to journalArticle

Wu, Chu Chiao ; Lee, Sunhee ; Malladi, Srinivas ; Chen, Miao Der ; Mastrandrea, Nicholas J. ; Zhang, Zhiwen ; Bratton, Shawn B. / The Apaf-1 apoptosome induces formation of caspase-9 homo- and heterodimers with distinct activities. In: Nature Communications. 2016 ; Vol. 7.
@article{c465994b3a8444a59898b869b2b6a1a4,
title = "The Apaf-1 apoptosome induces formation of caspase-9 homo- and heterodimers with distinct activities",
abstract = "According to dogma, initiator caspases are activated through proximity-induced homodimerization, but some studies infer that during apoptosis caspase-9 may instead form a holoenzyme with the Apaf-1 apoptosome. Using several biochemical approaches, including a novel site-specific crosslinking technique, we provide the first direct evidence that procaspase-9 homodimerizes within the apoptosome, markedly increasing its avidity for the complex and inducing selective intramolecular cleavage at Asp-315. Remarkably, however, procaspase-9 could also bind via its small subunit to the NOD domain in Apaf-1, resulting in the formation of a heterodimer that more efficiently activated procaspase-3. Following cleavage, the intersubunit linker (and associated conformational changes) in caspase-9-p35/p12 inhibited its ability to form homo- and heterodimers, but feedback cleavage by caspase-3 at Asp-330 removed the linker entirely and partially restored activity to caspase-9-p35/p10. Thus, the apoptosome mediates the formation of caspase-9 homo- and heterodimers, both of which are impacted by cleavage and contribute to its overall function.",
author = "Wu, {Chu Chiao} and Sunhee Lee and Srinivas Malladi and Chen, {Miao Der} and Mastrandrea, {Nicholas J.} and Zhiwen Zhang and Bratton, {Shawn B.}",
year = "2016",
month = "11",
day = "24",
doi = "10.1038/ncomms13565",
language = "English (US)",
volume = "7",
journal = "Nature Communications",
issn = "2041-1723",
publisher = "Nature Publishing Group",

}

TY - JOUR

T1 - The Apaf-1 apoptosome induces formation of caspase-9 homo- and heterodimers with distinct activities

AU - Wu, Chu Chiao

AU - Lee, Sunhee

AU - Malladi, Srinivas

AU - Chen, Miao Der

AU - Mastrandrea, Nicholas J.

AU - Zhang, Zhiwen

AU - Bratton, Shawn B.

PY - 2016/11/24

Y1 - 2016/11/24

N2 - According to dogma, initiator caspases are activated through proximity-induced homodimerization, but some studies infer that during apoptosis caspase-9 may instead form a holoenzyme with the Apaf-1 apoptosome. Using several biochemical approaches, including a novel site-specific crosslinking technique, we provide the first direct evidence that procaspase-9 homodimerizes within the apoptosome, markedly increasing its avidity for the complex and inducing selective intramolecular cleavage at Asp-315. Remarkably, however, procaspase-9 could also bind via its small subunit to the NOD domain in Apaf-1, resulting in the formation of a heterodimer that more efficiently activated procaspase-3. Following cleavage, the intersubunit linker (and associated conformational changes) in caspase-9-p35/p12 inhibited its ability to form homo- and heterodimers, but feedback cleavage by caspase-3 at Asp-330 removed the linker entirely and partially restored activity to caspase-9-p35/p10. Thus, the apoptosome mediates the formation of caspase-9 homo- and heterodimers, both of which are impacted by cleavage and contribute to its overall function.

AB - According to dogma, initiator caspases are activated through proximity-induced homodimerization, but some studies infer that during apoptosis caspase-9 may instead form a holoenzyme with the Apaf-1 apoptosome. Using several biochemical approaches, including a novel site-specific crosslinking technique, we provide the first direct evidence that procaspase-9 homodimerizes within the apoptosome, markedly increasing its avidity for the complex and inducing selective intramolecular cleavage at Asp-315. Remarkably, however, procaspase-9 could also bind via its small subunit to the NOD domain in Apaf-1, resulting in the formation of a heterodimer that more efficiently activated procaspase-3. Following cleavage, the intersubunit linker (and associated conformational changes) in caspase-9-p35/p12 inhibited its ability to form homo- and heterodimers, but feedback cleavage by caspase-3 at Asp-330 removed the linker entirely and partially restored activity to caspase-9-p35/p10. Thus, the apoptosome mediates the formation of caspase-9 homo- and heterodimers, both of which are impacted by cleavage and contribute to its overall function.

UR - http://www.scopus.com/inward/record.url?scp=84997531408&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84997531408&partnerID=8YFLogxK

U2 - 10.1038/ncomms13565

DO - 10.1038/ncomms13565

M3 - Article

C2 - 27882936

AN - SCOPUS:84997531408

VL - 7

JO - Nature Communications

JF - Nature Communications

SN - 2041-1723

M1 - 13565

ER -