Rev protein of human immunodeficiency virus type 1 and cellular exportin 1 protein relocalize each other to a subnucleolar structure.
The exportin 1/crml protein associates with leucine-rich nuclear export signals (NESs) and mediates nuclear export in various experimental systems. We show here that exportin 1 and the NES-containing human immunodeficiency virus (HIV) type 1 Rev protein relocalize each other to a characteristic dotlike structure within the nucleoli of human cells. On treatment with actinomycin D, Rev remains in these dots longer than in the rest of the nucleoli, arguing that the nucleolar dots do not represent sites of high transport turnover. Transient expression of exportin 1 strongly reduces the expression of a reporter that depends on the export of HIV RNA. When export of hepatitis B virus RNA and simple retrovirus RNA, as well as spliced mRNA, was assayed in this way, exportin 1 inhibited reporter expression to a lesser extent. Thus, an excess of exportin 1 may downregulate Rev-mediated RNA export by sequestering Rev to a subnucleolar structure.
Ristea
S
S
Institut für Virologie, Universität Marburg, Germany.
Dobbelstein
M
M
Roth
J
J
D001483:Base Sequence; D001693:Biological Transport, Active / Q000187:drug effects; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism*; D002451:Cell Compartmentation; D002466:Cell Nucleolus / Q000378:metabolism* / Q000648:ultrastructure / Q000821:virology*; D017931:DNA Primers / Q000235:genetics; D003609:Dactinomycin / Q000494:pharmacology; D015694:Gene Products, rev / Q000235:genetics / Q000378:metabolism*; D015497:HIV-1 / Q000235:genetics / Q000378:metabolism*; D006367:HeLa Cells; D006801:Humans; D028884:Karyopherins; D018160:Receptors, Cytoplasmic and Nuclear; D054321:rev Gene Products, Human Immunodeficiency Virus; D000097606:Exportin 1 Protein
D002352:Carrier Proteins; D017931:DNA Primers; D003609:Dactinomycin; D015694:Gene Products, rev; D028884:Karyopherins; D018160:Receptors, Cytoplasmic and Nuclear; D054321:rev Gene Products, Human Immunodeficiency Virus; D000097606:Exportin 1 Protein