Active cAMP-dependent protein kinase incorporated within highly purified HIV-1 particles is required for viral infectivity and interacts with viral capsid protein.
Host cell components, including protein kinases such as ERK-2/mitogen-activated protein kinase, incorporated within human immunodeficiency virus type 1 (HIV-1) virions play a pivotal role in the ability of HIV to infect and replicate in permissive cells. The present work provides evidence that the catalytic subunit of cAMP-dependent protein kinase (C-PKA) is packaged within HIV-1 virions as demonstrated using purified subtilisin-digested viral particles. Virus-associated C-PKA was shown to be enzymatically active and able to phosphorylate synthetic substrate in vitro. Suppression of virion-associated C-PKA activity by specific synthetic inhibitor had no apparent effect on viral precursor maturation and virus assembly. However, virus-associated C-PKA activity was demonstrated to regulate HIV-1 infectivity as assessed by single round infection assays performed by using viruses produced from cells expressing an inactive form of C-PKA. In addition, virus-associated C-PKA was found to co-precipitate with and to phosphorylate the CAp24gag protein. Altogether our results indicate that virus-associated C-PKA regulates HIV-1 infectivity, possibly by catalyzing phosphorylation of the viral CAp24gag protein.
Cartier
Christine
C
Laboratoire Infections Rétrovirales et Signalisation Cellulaire, Centre National de la Recherche Scientifique, UMR 5121-UM1, Institut de Biologie, CS 89508, 34960 Montpellier Cedex 2, France.
Hemonnot
Bénédicte
B
Gay
Bernard
B
Bardy
Martine
M
Sanchiz
Céline
C
Devaux
Christian
C
Briant
Laurence
L
D000818:Animals; D019556:COS Cells; D036022:Capsid Proteins / Q000378:metabolism*; D002448:Cell Adhesion; D002460:Cell Line; D002522:Chlorocebus aethiops; D017868:Cyclic AMP-Dependent Protein Kinases / Q000378:metabolism*; D004797:Enzyme-Linked Immunosorbent Assay; D016655:HIV Core Protein p24 / Q000235:genetics / Q000378:metabolism; D015497:HIV-1 / Q000201:enzymology / Q000472:pathogenicity / Q000502:physiology*; D006801:Humans; D007700:Kinetics; D016253:Microscopy, Immunoelectron; D019950:Mitogen-Activated Protein Kinase 1 / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014771:Virion / Q000201:enzymology; D014779:Virus Replication / Q000502:physiology*
D036022:Capsid Proteins; D016655:HIV Core Protein p24; D017868:Cyclic AMP-Dependent Protein Kinases; D019950:Mitogen-Activated Protein Kinase 1