HIV-1 Vpr Protein Enhances Proteasomal Degradation of MCM10 DNA Replication Factor through the Cul4-DDB1[VprBP] E3 Ubiquitin Ligase to Induce G2/M Cell Cycle Arrest

Bizhan Romani; Nima Shaykh Baygloo; Mohammad Reza Aghasadeghi; Elham Allahbakhshi

doi:10.1074/jbc.M115.641522

HIV-1 Vpr Protein Enhances Proteasomal Degradation of MCM10 DNA Replication Factor through the Cul4-DDB1[VprBP] E3 Ubiquitin Ligase to Induce G2/M Cell Cycle Arrest

J Biol Chem. 2015 Jul 10;290(28):17380-9. doi: 10.1074/jbc.M115.641522. Epub 2015 Jun 1.

Authors

Bizhan Romani¹, Nima Shaykh Baygloo², Mohammad Reza Aghasadeghi³, Elham Allahbakhshi⁴

Affiliations

¹ From the Department of Biology, Faculty of Science, University of Isfahan, Isfahan 81746-73441, the Cellular and Molecular Research Center (CMRC), Faculty of Medicine, Ahvaz Jundishapur University of Medical Sciences (AJUMS), Ahvaz 61357-15794, and.
² From the Department of Biology, Faculty of Science, University of Isfahan, Isfahan 81746-73441.
³ the Hepatitis and AIDS Department, Pasteur Institute of Iran, Tehran 13169-43551, Iran.
⁴ the Cellular and Molecular Research Center (CMRC), Faculty of Medicine, Ahvaz Jundishapur University of Medical Sciences (AJUMS), Ahvaz 61357-15794, and abakhshi_e@ajums.ac.ir.

Abstract

Human immunodeficiency virus type 1 Vpr is an accessory protein that induces G2/M cell cycle arrest. It is well documented that interaction of Vpr with the Cul4-DDB1[VprBP] E3 ubiquitin ligase is essential for the induction of G2/M arrest. In this study, we show that HIV-1 Vpr indirectly binds MCM10, a eukaryotic DNA replication factor, in a Vpr-binding protein (VprBP) (VprBP)-dependent manner. Binding of Vpr to MCM10 enhanced ubiquitination and proteasomal degradation of MCM10. G2/M-defective mutants of Vpr were not able to deplete MCM10, and we show that Vpr-induced depletion of MCM10 is related to the ability of Vpr to induce G2/M arrest. Our study demonstrates that MCM10 is the natural substrate of the Cul4-DDB1[VprBP] E3 ubiquitin ligase whose degradation is regulated by VprBP, but Vpr enhances the proteasomal degradation of MCM10 by interacting with VprBP.

Keywords: E3 ubiquitin ligase; HIV-1 Vpr; MCM10; VprBP; cell cycle; human immunodeficiency virus (HIV); proteasome; protein degradation; ubiquitin.

MeSH terms

Carrier Proteins / metabolism*
Cullin Proteins / metabolism
DNA Replication
DNA-Binding Proteins / metabolism
G2 Phase Cell Cycle Checkpoints
HEK293 Cells
HIV-1 / genetics
HIV-1 / pathogenicity
HIV-1 / physiology*
HeLa Cells
Host-Pathogen Interactions
Humans
Minichromosome Maintenance Proteins / antagonists & inhibitors
Minichromosome Maintenance Proteins / genetics
Minichromosome Maintenance Proteins / metabolism*
Models, Biological
Proteasome Endopeptidase Complex / metabolism
Protein Serine-Threonine Kinases
RNA, Small Interfering / genetics
Ubiquitin-Protein Ligases / metabolism*
vpr Gene Products, Human Immunodeficiency Virus / genetics
vpr Gene Products, Human Immunodeficiency Virus / metabolism*

Substances

Carrier Proteins
Cullin Proteins
DDB1 protein, human
DNA-Binding Proteins
MCM10 protein, human
RNA, Small Interfering
vpr Gene Products, Human Immunodeficiency Virus
vpr protein, Human immunodeficiency virus 1
Ubiquitin-Protein Ligases
DCAF1 protein, human
Protein Serine-Threonine Kinases
Proteasome Endopeptidase Complex
Minichromosome Maintenance Proteins