TY - JOUR
T1 - Conserved serines in simian immunodeficiency virus capsid are required for virus budding
AU - Rue, Sarah M.
AU - Roos, Jason W.
AU - Clements, Janice E.
AU - Barber, Sheila A.
N1 - Funding Information:
We thank Debbie Hauer for her technical assistance in developing the SIV CA substitution mutants, John Bernbaum for his detailed EM analyses, and Dr. Gary Ketner for helpful discussions. The following reagents were obtained through the AIDS Research and Reference Reagent Program, NIAID, NIH: p239SpSp5′ and p239SpE3′ from Dr. Ronald Desrosiers. This work was supported by grants to J.E.C. from the National Institutes of Health (NS07392, MH70306, and NS47984).
PY - 2005/5/25
Y1 - 2005/5/25
N2 - The simian immunodeficiency virus (SIV) capsid protein (CA), a constituent of the Pr55Gag polyprotein, is phosphorylated in virions but not in virus-producing cells (Rue, S.M., Roos, J.W., Tarwater, P.M., Clements, J.E., Barber, S.A., 2005. Phosphorylation and proteolytic cleavage of gag proteins in budded simian immunodeficiency virus. J. Virol. 79 (4), 2484-2492.). Using phosphoamino acid analysis of CA, we show that serine is the primary phosphate acceptor. A series of substitution mutants of serines in the CA domain of Pr55Gag were constructed in the infectious viral clone SIVmac239. These virus mutants were examined for defects in virus replication and virion infectivity, release, and morphology, as well as alterations in phosphorylation of CA-containing proteins. Although the virus mutants exhibited a number of replication defects, none of these defects could be directly attributed to aberrant CA phosphorylation. A novel defect was a block in early budding, which was common among several virus mutants with substitutions in the CA N terminus. Together, these results indicate that certain residues in the CA N terminus are crucial for early budding events.
AB - The simian immunodeficiency virus (SIV) capsid protein (CA), a constituent of the Pr55Gag polyprotein, is phosphorylated in virions but not in virus-producing cells (Rue, S.M., Roos, J.W., Tarwater, P.M., Clements, J.E., Barber, S.A., 2005. Phosphorylation and proteolytic cleavage of gag proteins in budded simian immunodeficiency virus. J. Virol. 79 (4), 2484-2492.). Using phosphoamino acid analysis of CA, we show that serine is the primary phosphate acceptor. A series of substitution mutants of serines in the CA domain of Pr55Gag were constructed in the infectious viral clone SIVmac239. These virus mutants were examined for defects in virus replication and virion infectivity, release, and morphology, as well as alterations in phosphorylation of CA-containing proteins. Although the virus mutants exhibited a number of replication defects, none of these defects could be directly attributed to aberrant CA phosphorylation. A novel defect was a block in early budding, which was common among several virus mutants with substitutions in the CA N terminus. Together, these results indicate that certain residues in the CA N terminus are crucial for early budding events.
KW - Budding
KW - Capsid
KW - Gag
KW - Phosphorylation
KW - SIV
KW - Serine
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U2 - 10.1016/j.virol.2005.03.006
DO - 10.1016/j.virol.2005.03.006
M3 - Article
C2 - 15866069
AN - SCOPUS:18144405321
SN - 0042-6822
VL - 336
SP - 37
EP - 50
JO - Virology
JF - Virology
IS - 1
ER -