TY - JOUR
T1 - Requirement of an additional Sam68 domain for inhibition of human immunodeficiency virus type 1 replication by Sam68 dominant negative mutants lacking the nuclear localization signal
AU - Zhang, Jizhong
AU - Liu, Ying
AU - Henao, Jorge
AU - Rugeles, Maria T.
AU - Li, Jinliang
AU - Chen, Tie
AU - He, Johnny J.
N1 - Funding Information:
This work was supported by the grants R01NS39804 and R01MH65158 (to JJH) from the National Institutes of Health.
PY - 2005/12/19
Y1 - 2005/12/19
N2 - Human immunodeficiency virus type 1 (HIV-1) replication requires active nuclear export of unspliced and incompletely spliced HIV-1 RNA transcripts. This process is evolutionally made possible by expression of HIV-1 Rev, one of the three HIV-1 proteins encoded by completely spliced HIV-1 RNAs. Evidence has accumulated to suggest that Sam68 plays an important role in HIV-1 replication through HIV-1 Rev protein. In the present study, we further examined the structure-function relationship of Sam68 protein in relation to HIV-1 replication. We identified a Sam68 domain located between aa269 and aa321 to be involved in the HIV-inhibitory effects of Sam68 dominant negative mutants lacking the nuclear localization signal (NLS). Deletion of this domain abrogated inhibition of HIV-1 replication by these mutants. HIV-1 Rev protein appeared to mediate the HIV-inhibitory effects of these mutants and by this domain, as assessed by Rev-dependent chloramphenicol acetyltransferase reporter gene assay, in trans rev-defective HIV-1 complementation assay, and RNase protection assay. The HIV-inhibitory mutants containing this domain were further found to have diminished binding affinity to the wild-type Sam68 and to be associated with cytoplasmic retention of exclusively nuclear localized wild type Sam68. Taken together, these results further ascertain the important role of Sam68 in HIV-1 Rev function and viral replication, and suggest that the HIV-inhibitory effects of Sam68 dominant negative mutants directly result from their binding to endogenous Sam68 and their interference with nuclear localization of endogenous Sam68.
AB - Human immunodeficiency virus type 1 (HIV-1) replication requires active nuclear export of unspliced and incompletely spliced HIV-1 RNA transcripts. This process is evolutionally made possible by expression of HIV-1 Rev, one of the three HIV-1 proteins encoded by completely spliced HIV-1 RNAs. Evidence has accumulated to suggest that Sam68 plays an important role in HIV-1 replication through HIV-1 Rev protein. In the present study, we further examined the structure-function relationship of Sam68 protein in relation to HIV-1 replication. We identified a Sam68 domain located between aa269 and aa321 to be involved in the HIV-inhibitory effects of Sam68 dominant negative mutants lacking the nuclear localization signal (NLS). Deletion of this domain abrogated inhibition of HIV-1 replication by these mutants. HIV-1 Rev protein appeared to mediate the HIV-inhibitory effects of these mutants and by this domain, as assessed by Rev-dependent chloramphenicol acetyltransferase reporter gene assay, in trans rev-defective HIV-1 complementation assay, and RNase protection assay. The HIV-inhibitory mutants containing this domain were further found to have diminished binding affinity to the wild-type Sam68 and to be associated with cytoplasmic retention of exclusively nuclear localized wild type Sam68. Taken together, these results further ascertain the important role of Sam68 in HIV-1 Rev function and viral replication, and suggest that the HIV-inhibitory effects of Sam68 dominant negative mutants directly result from their binding to endogenous Sam68 and their interference with nuclear localization of endogenous Sam68.
UR - http://www.scopus.com/inward/record.url?scp=28044442308&partnerID=8YFLogxK
U2 - 10.1016/j.gene.2005.06.043
DO - 10.1016/j.gene.2005.06.043
M3 - Article
C2 - 16236470
AN - SCOPUS:28044442308
SN - 0378-1119
VL - 363
SP - 67
EP - 76
JO - Gene
JF - Gene
IS - 1-2
ER -