Effect of Rev on the intranuclear localization of HIV-1 unspliced RNA.
Human immunodeficiency virus type 1 (HIV-1) Rev is a 19-kDa regulatory protein which binds to unspliced and partially spliced HIV-1 RNAs. Export, splicing, stability, and translation of HIV-1 RNAs are influenced by Rev. To further understand the effect of Rev on HIV-1 RNA splicing, the intranuclear localization of unspliced HIV-1 RNA and a cellular splicing factor was examined in the presence and absence of Rev. Splicing component-35 (SC-35) is an essential SR protein splicing factor which localizes into 20-40 nuclear granules (Fu, X. D., and Maniatis, T. Nature 343 (6257), 437-441, 1990). Laser scanning confocal microscopy was utilized to examine the colocalization of unspliced HIV-1 RNA and SC-35-containing granules. In the presence of Rev, many of the SC-35-containing granules were colocalized on their edges or completely colocalized with HIV-1 unspliced RNA speckles. In the absence of Rev, however, little colocalization of the unspliced HIV-1 RNA speckles and the SC-35-containing granules was observed. Quantitative RT-PCR was utilized to examine the effect of Rev on the level of fully spliced HIV-1 RNA. In the presence of Rev, a decrease in the level of fully spliced HIV-1 RNA was observed. Thus both the intranuclear localization and posttranscriptional processing of HIV-1 unspliced RNA are affected by Rev.
Favaro
J P
JP
Department of Microbiology and Immunology, Medical University of South Carolina, Charleston, South Carolina, 29425-2230, USA.
Borg
K T
KT
Arrigo
S J
SJ
Schmidt
M G
MG
D002460:Cell Line; D002467:Cell Nucleus / Q000378:metabolism / Q000821:virology; D015694:Gene Products, rev / Q000235:genetics* / Q000378:metabolism*; D015757:Genes, rev; D015497:HIV-1 / Q000235:genetics* / Q000378:metabolism*; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D018613:Microscopy, Confocal; D009154:Mutation; D009687:Nuclear Proteins / Q000378:metabolism; D012326:RNA Splicing; D012367:RNA, Viral / Q000235:genetics* / Q000378:metabolism*; D012261:Ribonucleoproteins; D000068103:Serine-Arginine Splicing Factors; D014162:Transfection; D054321:rev Gene Products, Human Immunodeficiency Virus
D015694:Gene Products, rev; D009687:Nuclear Proteins; D012367:RNA, Viral; D012261:Ribonucleoproteins; D054321:rev Gene Products, Human Immunodeficiency Virus; C073288:SRSF2 protein, human; D000068103:Serine-Arginine Splicing Factors