Covalent conjugation of the equine infectious anemia virus Gag with SUMO.
The conjugation of small ubiquitin-like modifier (SUMO) to the target protein, namely, SUMOylation, is involved in the regulation of many important biological events including host-pathogen interaction. Some viruses have evolved to exploit the host SUMOylation machinery to modify their own protein. Retroviral Gag protein plays critical roles in the viral life cycle. The HIV-1 p6 and the Moloney murine leukemia virus CA have been reported to be conjugated with SUMO. In this study, we report for the first time, to our knowledge, the covalent conjugation of equine infectious anemia virus (EIAV) Gag with SUMO. The C-terminal p9 domain of Gag is a main target for SUMOylation and SUMO is attached to multiple sites of p9, including K30 whose mutation abolished p9 SUMOylation completely. The SUMOylation of p9, but not the p9-K30 mutant, was also detected in equine fibroblastic cells ATCC®CCL-57™. Ubc9 and its C93 residue are indispensable for the SUMOylation of p9. Using confocal microscopy, it is found that EIAV Gag localizes primarily, if not exclusively, in the cytoplasm of the cell and the co-localization of EIAV Gag with Ubc9 was observed. Our findings that EIAV Gag is SUMOylated at p9-K30, together with previous findings on the defects of p9-K30 mutant in viral DNA translocation from cytoplasm to the nucleus, suggests that SUMOylation of Gag may be involved in such functions.
TEDA Institute of Biological Sciences and Biotechnology, Nankai University, 23 Hongda Street, TEDA, Tianjin 300457, China; Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, 23 Hongda Street, TEDA, Tianjin 300457, China; Tianjin Key Laboratory of Microbial Functional Genomics, 23 Hongda Street, TEDA, Tianjin 300457, China.
Jinzhong
J
Wang
TEDA Institute of Biological Sciences and Biotechnology, Nankai University, 23 Hongda Street, TEDA, Tianjin 300457, China.
Shuping
S
Wen
TEDA Institute of Biological Sciences and Biotechnology, Nankai University, 23 Hongda Street, TEDA, Tianjin 300457, China.
Rui
R
Zhao
TEDA Institute of Biological Sciences and Biotechnology, Nankai University, 23 Hongda Street, TEDA, Tianjin 300457, China.
Jing
J
Qi
TEDA Institute of Biological Sciences and Biotechnology, Nankai University, 23 Hongda Street, TEDA, Tianjin 300457, China.
Zhao
Z
Liu
TEDA Institute of Biological Sciences and Biotechnology, Nankai University, 23 Hongda Street, TEDA, Tianjin 300457, China.
Weiwei
W
Li
TEDA Institute of Biological Sciences and Biotechnology, Nankai University, 23 Hongda Street, TEDA, Tianjin 300457, China.
Jing
J
An
Nebraska Center for Virology and School of Biological Sciences, University of Nebraska, Lincoln, NE 68583, USA. Electronic address: cwood1@unl.edu.
Charles
C
Wood
TEDA Institute of Biological Sciences and Biotechnology, Nankai University, 23 Hongda Street, TEDA, Tianjin 300457, China; Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, 23 Hongda Street, TEDA, Tianjin 300457, China; Tianjin Key Laboratory of Microbial Functional Genomics, 23 Hongda Street, TEDA, Tianjin 300457, China. Electronic address: yingwang@nankai.edu.cn.
Ying
Y
Wang
D000595:Amino Acid Sequence; D000818:Animals; D002460:Cell Line; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D005347:Fibroblasts / Q000378:metabolism / Q000821:virology; D005786:Gene Expression Regulation; D015683:Gene Products, gag / Q000235:genetics* / Q000378:metabolism; D057809:HEK293 Cells; D006736:Horses; D054884:Host-Pathogen Interactions; D006801:Humans; D004860:Infectious Anemia Virus, Equine / Q000235:genetics* / Q000378:metabolism; D008239:Lysine / Q000378:metabolism*; D009154:Mutation; D000072417:Protein Domains; D025842:SUMO-1 Protein / Q000235:genetics* / Q000378:metabolism; D015398:Signal Transduction; D058207:Sumoylation; D044763:Ubiquitin-Conjugating Enzymes / Q000235:genetics* / Q000378:metabolism; D000098843:Ubiquitin-Conjugating Enzyme UBC9
D015683:Gene Products, gag; D025842:SUMO-1 Protein; D044763:Ubiquitin-Conjugating Enzymes; D000098843:Ubiquitin-Conjugating Enzyme UBC9; D008239:Lysine
EIAV; Gag; K30; SUMO; Ubc9; p9