Mason–Pfizer monkey virus Gag proteins interact with the human sumo conjugating enzyme, hUbc9

• Published in: Virology (New York, N.Y.) Vol. 314; no. 1; pp. 62 - 73
• Main Authors: Weldon, Robert A, Sarkar, Pushpita, Brown, Shanna M, Weldon, Sally K
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 15.09.2003
• Subjects: Animals; Capsid; COS Cells; COS-1 cells; Cytoplasm - metabolism; Gag; Gene Products, gag - chemistry; Gene Products, gag - genetics; Gene Products, gag - metabolism; HeLa Cells; Humans; Ligases - genetics; Ligases - metabolism; Mason-Pfizer monkey virus - metabolism; Mason–Pfizer monkey virus; Protein Precursors - metabolism; Retroviridae; Two-Hybrid System Techniques; Ubc9; Ubiquitin-Conjugating Enzymes; Virus assembly; Virus Replication; Yeast two-hybrid screen; Virus assembly; Yeast two-hybrid screen; COS-1 cells; Retroviridae; Ubc9; Gag; Capsid; Mason–Pfizer monkey virus
• ISSN: 0042-6822; 1096-0341
• DOI: 10.1016/S0042-6822(03)00348-9

Retroviral Gag proteins function during early and late stages of the viral life cycle. To gain additional insight into the cellular requirements for viral replication, a two-hybrid screen was used to identify cellular proteins that interact with the Mason–Pfizer monkey virus Gag protein. One of the cellular proteins found was identified as hUbc9, a nuclear pore-associated E2 SUMO conjugating enzyme. In vitro protein interaction assays verified the association and mapped the interaction domain to the CA protein. In vivo, hUbc9 and Gag colocalized in the cytoplasm as discrete foci near the nuclear membrane. In addition, overexpression of hUbc9 in cells caused a fraction of Gag to colocalize with hUbc9 in the nucleus. These experiments demonstrate that hUbc9 and Gag interact in cells, strengthen the hypothesis that Gag proteins transiently associate with the nuclear compartment during viral replication, and suggest that hUbc9 plays a role in this process.