YGLF motif in the Kaposi sarcoma herpes virus G-protein-coupled receptor adjusts NF-κB activation and paracrine actions

Oncogene. 2014 Dec 4;33(49):5609-18. doi: 10.1038/onc.2013.503. Epub 2013 Dec 2.

Abstract

Kaposi sarcoma (KS) and primary effusion lymphoma (PEL) are two pathologies associated with KS herpes virus (KSHV/HHV-8) infection. KSHV genome contains several oncogenes, among which, the viral G-protein-coupled receptor (vGPCR open reading frame 74) has emerged as a major factor in KS pathogenicity. Indeed, vGPCR is a constitutively active receptor, whose expression is sufficient to drive cell transformation in vitro and tumour development in mice. However, neither the role of vGPCR in KSHV-infected B-lymphocytes nor the molecular basis for its constitutive activation is well understood. Here, we show that vGPCR expression contributes to nuclear factor-κB (NF-κB)-dependent cellular survival in both PEL cells and primary B cells from HIV-negative KS patients. We further identified within vGPCR an AP2 consensus binding motif, Y326GLF, that directs its localization between the plasma membrane and clathrin-coated vesicles. The introduction of a mutation in this site (Y326A) increased NF-κB activity and proinflammatory cytokines production. This correlated with exacerbated morphological rearrangement, migration and proliferation of non-infected monocytes. Collectively, our work raises the possibility that KSHV-infected B-lymphocytes use vGPCR to impact ultimately the immune response and communication within the tumour microenvironment in KSHV-associated pathologies.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Motifs
  • B-Lymphocytes / cytology
  • B-Lymphocytes / metabolism
  • B-Lymphocytes / virology
  • Binding Sites
  • Cell Membrane / metabolism
  • Cell Membrane / virology
  • Cell Movement
  • Clathrin / chemistry
  • Cytokines / metabolism
  • Flow Cytometry
  • HEK293 Cells
  • HIV Infections
  • HeLa Cells
  • Herpesvirus 8, Human / genetics*
  • Humans
  • Inflammation
  • Jurkat Cells
  • Leukocytes, Mononuclear / cytology
  • Mutation
  • NF-kappa B p50 Subunit / metabolism*
  • Open Reading Frames
  • RNA, Small Interfering / metabolism
  • Receptors, G-Protein-Coupled / metabolism*
  • Sarcoma, Kaposi / virology*
  • Signal Transduction

Substances

  • Clathrin
  • Cytokines
  • NF-kappa B p50 Subunit
  • NFKB1 protein, human
  • RNA, Small Interfering
  • Receptors, G-Protein-Coupled