Interaction of human immunodeficiency virus type I Rev protein with nuclear scaffold nucleoside triphosphatase activity.
Human immunodeficiency virus type I encodes a regulatory protein, termed Rev, which is associated with the appearance of unspliced and partially spliced viral RNAs in the cytoplasm. Rev is believed to function via interaction with a sequence element in the env region of the viral RNA, termed the Rev-responsive element (RRE). In this study, we use a stably transfected, Rev-producing mouse cell line to show that low, functional levels of Rev are associated with the nuclear scaffold (NS). Immunohistochemical studies localize Rev to the NS. Furthermore, immunoblot analyses demonstrate the presence of Rev in NS preparations isolated from Rev-producing cells and document binding of purified Rev protein to isolated NS or to cloned lamin C in vitro. Results with an in vitro RNA transport assay suggest that Rev is associated with a significant defect in transport of RNAs which lack RRE, whereas transport of RRE-containing transcripts proceeds efficiently. This Rev-induced transport defect appears to be mediated via direct inhibition of NS nucleoside triphosphatase, an enzyme thought to be involved in the nucleocytoplasmic transport process. NS preparations isolated from Rev-producing cells show a significantly lower nucleoside triphosphatase activity than those from control preparations. Addition of Rev protein to isolated NS produces a significant inhibition of NS nucleoside triphosphatase activity, which is specifically reversed by addition of RRE transcripts. These data suggest that a major aspect of Rev function may involve selective modulation of host cell nucleocytoplasmic transport mechanisms via interaction with the NS.
Clawson
G A
GA
Department of Pathology, Pennsylvania State University, Hershey 17033.
Song
Y L
YL
Schwartz
A M
AM
Shukla
R R
RR
Patel
S G
SG
Connor
L
L
Blankenship
L
L
Hatem
C
C
Kumar
A
A
D000818:Animals; D001692:Biological Transport; D002460:Cell Line; D015694:Gene Products, rev / Q000378:metabolism*; D015752:Genes, env; D015497:HIV-1 / Q000378:metabolism*; D034904:Lamin Type A; D034882:Lamins; D051379:Mice; D015530:Nuclear Matrix / Q000378:metabolism*; D009687:Nuclear Proteins / Q000378:metabolism; D043583:Nucleoside-Triphosphatase; D010744:Phosphoric Monoester Hydrolases / Q000037:antagonists & inhibitors* / Q000378:metabolism; D012323:RNA Processing, Post-Transcriptional; D012367:RNA, Viral / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D012045:Regulatory Sequences, Nucleic Acid; D054321:rev Gene Products, Human Immunodeficiency Virus
D015694:Gene Products, rev; D034904:Lamin Type A; D034882:Lamins; D009687:Nuclear Proteins; D012367:RNA, Viral; D011993:Recombinant Fusion Proteins; C440308:lamin C; D054321:rev Gene Products, Human Immunodeficiency Virus; D010744:Phosphoric Monoester Hydrolases; D043583:Nucleoside-Triphosphatase