Targeting γ-herpesvirus 68 Bcl-2-mediated down-regulation of autophagy

Minfei Su, Yang Mei, Ruslan Sanishvili, Beth Levine, Christopher L. Colbert, Sangita Sinha

Research output: Contribution to journalArticle

28 Scopus citations

Abstract

γ-herpesviruses (γHVs) are common human pathogens that encode homologs of the anti-apoptotic cellular Bcl-2 proteins, which are critical to viral reactivation and oncogenic transformation. The murine γHV68 provides a tractable in vivo model for understanding general features of these important human pathogens. Bcl-XL, a cellular Bcl-2 homolog, and the murine γHV68 Bcl-2 homolog, M11, both bind to a BH3 domain within the key autophagy effector Beclin 1 with comparable affinities, resulting in the down-regulation of Beclin 1-mediated autophagy. Despite this similarity, differences in residues lining the binding site of M11 and Bcl-XL dictate varying affinities for the different BH3 domain-containing proteins. Here we delineate Beclin 1 differential specificity determinants for binding to M11 or Bcl-XL by quantifying autophagy levels in cells expressing different Beclin 1 mutants and either M11 or Bcl-XL, and we show that a G120E/D121A Beclin 1 mutant selectively prevents downregulation of Beclin 1-mediated autophagy by Bcl-XL, but not by M11. We use isothermal titration calorimetry to identify a Beclin 1 BH3 domain-derived peptide that selectively binds to M11, but not to Bcl-XL. The x-ray crystal structure of this peptide bound to M11 reveals the mechanism by which the M11 BH3 domain-binding groove accommodates this M11-specific peptide. This information was used to develop a cell-permeable peptide inhibitor that selectively inhibits M11-mediated, but not Bcl-XL-mediated, down-regulation of autophagy.

Original languageEnglish (US)
Pages (from-to)8029-8040
Number of pages12
JournalJournal of Biological Chemistry
Volume289
Issue number12
DOIs
StatePublished - Mar 21 2014

ASJC Scopus subject areas

  • Biochemistry
  • Molecular Biology
  • Cell Biology

Fingerprint Dive into the research topics of 'Targeting γ-herpesvirus 68 Bcl-2-mediated down-regulation of autophagy'. Together they form a unique fingerprint.

Cite this