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Phosphorylation-dependent human immunodeficiency virus type 1 infection and nuclear targeting of viral DNA

A G Bukrinskaya1, A Ghorpade, N K Heinzinger

  • 1Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha 68198-5120, USA.

Proceedings of the National Academy of Sciences of the United States of America
|January 9, 1996
PubMed

Insights

Phosphorylation of the HIV-1 gag MA protein is crucial for its nuclear targeting and subsequent viral replication. Inhibiting this phosphorylation significantly impairs virus infectivity by blocking nuclear localization of viral DNA.

Area of Science:

  • Virology
  • Molecular Biology
  • Cellular Biology

Background:

  • The gag MA protein of human immunodeficiency virus type 1 (HIV-1) plays dual roles in virus replication.
  • During assembly, myristoylation targets gag MA to the membrane; during infection, its nuclear targeting signal aids provirus establishment.

Purpose of the Study:

  • To investigate the role of gag MA phosphorylation in HIV-1 replication.
  • To determine if phosphorylation regulates gag MA's transition from membrane association to nuclear translocation.

Main Methods:

  • Analysis of gag MA phosphorylation on tyrosine and serine residues.
  • Assessment of gag MA nuclear localization following phosphorylation.
  • Inhibition of gag MA phosphorylation and its effect on viral infectivity.
  • Identification of kinases associated with HIV-1 virions.

Main Results:

  • Phosphorylation of gag MA on tyrosine and serine facilitates its dissociation from the membrane.
  • This dissociation allows gag MA to translocate to the nucleus.
  • Inhibiting gag MA phosphorylation on tyrosine or serine blocks nuclear targeting of viral nucleic acids and reduces virus infectivity.
  • A serine/threonine kinase was found to be associated with HIV-1 virions.

Conclusions:

  • Gag MA phosphorylation is a novel regulatory mechanism controlling HIV-1 infectivity.
  • Phosphorylation is essential for gag MA's nuclear import, facilitating provirus formation.
  • This finding highlights a new regulatory pathway in primate lentivirus replication.

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