The ataxia telangiectasia-mutated and Rad3-related protein is dispensable for retroviral integration.
Integration into the host cell DNA is an essential part of the retroviral life cycle and is required for the productive replication of a retrovirus. Retroviral integration involves cleavage of the host DNA and insertion of the viral DNA, forming an integration intermediate that contains two gaps, each with a viral 5' flap. The flaps are then removed, and the gap is filled by as yet unidentified nuclease and polymerase activities. It is thought that repair of these gaps flanking the site of retroviral integration is achieved by host DNA repair machinery. The ATM and Rad3-related protein (ATR) is a member of the phosphatidylinositol 3 kinase-related family of protein kinases that play a major role in sensing and triggering repair of DNA lesions in mammalian cells. In an effort to examine the role of ATR in retroviral integration, we used RNA interference to selectively downregulate ATR and measured integration efficiency. In addition, we examined the possible role that Vpr may play in enhancing integration and, in particular, whether activation of ATR by Vpr (Roshal et al., J. Biol. Chem. 278:25879-25886, 2003) will favor human immunodeficiency virus type 1 integration. We conclude that cells in which ATR has been depleted are competent for retroviral integration. We also conclude that the presence of Vpr as a virion-bound protein does not enhance integration of a lentivirus vector in dividing cells.
Dehart
Jason L
JL
Division of Cellular Biology and Immunology, Department of Pathology, University of Utah School of Medicine, 30 N 1900 East, SOM 5C210, Salt Lake City, UT 84132, USA.
Andersen
Joshua L
JL
Zimmerman
Erik S
ES
Ardon
Orly
O
An
Dong Sung
DS
Blackett
Jana
J
Kim
Baek
B
Planelles
Vicente
V
D000818:Animals; D064007:Ataxia Telangiectasia Mutated Proteins; D018797:Cell Cycle Proteins / Q000235:genetics / Q000378:metabolism*; D002460:Cell Line; D004279:DNA, Viral / Q000235:genetics; D015536:Down-Regulation; D016336:Gene Products, vpr / Q000235:genetics / Q000378:metabolism; D005822:Genetic Vectors; D015497:HIV-1 / Q000235:genetics; D006367:HeLa Cells; D006801:Humans; D051379:Mice; D017346:Protein Serine-Threonine Kinases / Q000235:genetics / Q000378:metabolism*; D034622:RNA Interference; D012190:Retroviridae / Q000235:genetics*; D014161:Transduction, Genetic; D016662:Virus Integration; D054325:vpr Gene Products, Human Immunodeficiency Virus
D018797:Cell Cycle Proteins; D004279:DNA, Viral; D016336:Gene Products, vpr; D054325:vpr Gene Products, Human Immunodeficiency Virus; C576597:ATR protein, human; D064007:Ataxia Telangiectasia Mutated Proteins; D017346:Protein Serine-Threonine Kinases