Short communication: identification of the conformational requirement for the specificities of coreceptors for human and simian immunodeficiency viruses

AIDS Res Hum Retroviruses. 2010 Mar;26(3):321-8. doi: 10.1089/aid.2009.0161.

Abstract

More than 10 G protein-coupled receptors (GPCRs) work as coreceptors for human and simian immunodeficiency viruses (HIVs/SIVs); however, structural features critical for coreceptor activity have not been identified. Our objective was to elucidate the structural requirement of coreceptor activities. Amino-terminal regions (NTRs), extracellular loops (ECLs), and the undecapeptidyl arch (UPA) in the second ECL have been shown to be important for coreceptor function. We made chimeric coreceptors for these regions between CCR5 and GPR1, which is genetically distant from CCR5, and analyzed their activities. The coreceptor activity and specificity of CCR5 were maintained when its NTR or UPA was replaced with GPR1. In contrast, the GPR1 chimera with CCR5 NTR was used by HIV-1 strains that can use only CCR5, but not both CCR5 and CXCR4, or GPR1. GPR1 chimera with CCR5 UPA almost lost activity. All ECL chimeras could hardly maintain activity. Thus, CCR5 is more flexibly acceptable to heterologous NTR and UPA than GPR1, suggesting the existence of conformational differences made by the integration of multiple extracellular regions. This conformation may specifically interact with HIV-1 in a strain-dependent manner. Identification of a factor that is critical to make this conformation will contribute to understanding the mechanism of coreceptor function of GPCRs. For this, the coreceptor activity of GPR1, which is genetically distant from CCR5, will be a useful tool.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cell Line, Tumor
  • HIV Infections / metabolism*
  • HIV Infections / virology
  • HIV-1 / physiology*
  • HIV-2 / physiology*
  • Host-Pathogen Interactions
  • Humans
  • Phylogeny
  • Protein Conformation
  • Receptors, CCR5 / chemistry*
  • Receptors, CCR5 / genetics
  • Receptors, CCR5 / metabolism
  • Receptors, G-Protein-Coupled / chemistry*
  • Receptors, G-Protein-Coupled / genetics
  • Receptors, G-Protein-Coupled / metabolism
  • Recombinant Fusion Proteins / biosynthesis
  • Simian Acquired Immunodeficiency Syndrome / metabolism*
  • Simian Acquired Immunodeficiency Syndrome / virology
  • Simian Immunodeficiency Virus / physiology*
  • Substrate Specificity

Substances

  • GPR1 protein, human
  • Receptors, CCR5
  • Receptors, G-Protein-Coupled
  • Recombinant Fusion Proteins