Structural and Functional Study of Apoptosis-linked Gene-2·Heme-binding Protein 2 Interactions in HIV-1 Production

J Biol Chem. 2016 Dec 23;291(52):26670-26685. doi: 10.1074/jbc.M116.752444. Epub 2016 Oct 26.

Abstract

In the HIV-1 replication cycle, the endosomal sorting complex required for transport (ESCRT) machinery promotes viral budding and release in the late stages. In this process, the ESCRT proteins, ALIX and TSG101, are recruited through interactions with HIV-1 Gag p6. ALG-2, also known as PDCD6, interacts with both ALIX and TSG101 and bridges ESCRT-III and ESCRT-I. In this study, we show that ALG-2 affects HIV-1 production negatively at both the exogenous and endogenous levels. Through a yeast two-hybrid screen, we identified HEBP2 as the binding partner of ALG-2, and we solved the crystal structure of the ALG-2·HEBP2 complex. The function of ALG-2·HEBP2 complex in HIV-1 replication was further explored. ALG-2 inhibits HIV-1 production by affecting Gag expression and distribution, and HEBP2 might aid this process by tethering ALG-2 in the cytoplasm.

Keywords: ALG-2; Gag expression; crystal structure; human immunodeficiency virus (HIV); inhibition mechanism; protein-protein interaction; transport; viral replication.

MeSH terms

  • Apoptosis
  • Apoptosis Regulatory Proteins / chemistry
  • Apoptosis Regulatory Proteins / genetics
  • Apoptosis Regulatory Proteins / metabolism*
  • Calcium-Binding Proteins / chemistry
  • Calcium-Binding Proteins / genetics
  • Calcium-Binding Proteins / metabolism*
  • Cell Cycle Proteins / chemistry
  • Cell Cycle Proteins / genetics
  • Cell Cycle Proteins / metabolism*
  • Crystallization
  • Crystallography, X-Ray
  • DNA-Binding Proteins / chemistry
  • DNA-Binding Proteins / genetics
  • DNA-Binding Proteins / metabolism*
  • Endosomal Sorting Complexes Required for Transport / chemistry
  • Endosomal Sorting Complexes Required for Transport / genetics
  • Endosomal Sorting Complexes Required for Transport / metabolism*
  • HIV Infections / metabolism*
  • HIV Infections / virology
  • HIV-1 / physiology*
  • HeLa Cells
  • Heme-Binding Proteins
  • Hemeproteins / chemistry
  • Hemeproteins / genetics
  • Hemeproteins / metabolism*
  • Humans
  • Pregnancy Proteins / chemistry
  • Pregnancy Proteins / genetics
  • Pregnancy Proteins / metabolism*
  • Protein Binding
  • Protein Conformation
  • Protein Transport
  • Transcription Factors / chemistry
  • Transcription Factors / genetics
  • Transcription Factors / metabolism*
  • Virus Replication / physiology*

Substances

  • Apoptosis Regulatory Proteins
  • Calcium-Binding Proteins
  • Cell Cycle Proteins
  • DNA-Binding Proteins
  • Endosomal Sorting Complexes Required for Transport
  • HEBP2 protein, human
  • Heme-Binding Proteins
  • Hemeproteins
  • PDCD6 protein, human
  • PDCD6IP protein, human
  • Pregnancy Proteins
  • Transcription Factors
  • Tsg101 protein