Human immunodeficiency virus type 1 Rev is required in vivo for binding of poly(A)-binding protein to Rev-dependent RNAs.
In the absence of Rev or the Rev-responsive element, the Rev-dependent human immunodeficiency virus type 1 (HIV-1) RNAs do not behave as mRNAs; rather, they exhibit nuclear defects in splicing and/or nuclear export and cytoplasmic defects in stability and translation. A translational initiation factor, eIF-5A, has recently been shown to bind specifically to the Rev activation domain. As the binding of poly(A)-binding protein 1 (PAB1) to the poly(A) tail of mRNAs is involved in both the stability and translation of cytoplasmic mRNAs, we investigated whether Rev might influence the association of PAB1 with cytoplasmic HIV-1 RNAs. Antibodies were generated against PAB1. We used these antibodies in an immunoprecipitation assay to detect specific binding of PAB1 to cytoplasmic mRNAs. We found that in the presence of Rev, PAB1 was associated with Rev-dependent and Rev-independent RNAs in the cytoplasm of transfected cells. However, in the absence of functional Rev, we found little or no PAB1 associated with Rev-dependent RNAs. These RNAs were capable of binding PAB1 in vitro. These results demonstrate that HIV-1 RNAs are defective in PAB1 association in the absence of Rev.
Campbell
L H
LH
Department of Microbiology and Immunology, Medical University of South Carolina, Charleston 29425-2230.
Borg
K T
KT
Haines
J K
JK
Moon
R T
RT
Schoenberg
D R
DR
Arrigo
S J
SJ
D000595:Amino Acid Sequence; D001483:Base Sequence; D002460:Cell Line; D003593:Cytoplasm / Q000378:metabolism; D015967:Gene Expression Regulation, Viral; D015694:Gene Products, rev / Q000378:metabolism*; D015497:HIV-1 / Q000235:genetics*; D006801:Humans; D066298:In Vitro Techniques; D008969:Molecular Sequence Data; D015345:Oligonucleotide Probes / Q000737:chemistry; D010455:Peptides / Q000737:chemistry; D039102:Poly(A)-Binding Proteins; D014176:Protein Biosynthesis; D012333:RNA, Messenger / Q000378:metabolism; D012367:RNA, Viral / Q000378:metabolism; D016601:RNA-Binding Proteins / Q000378:metabolism*; D054321:rev Gene Products, Human Immunodeficiency Virus
D015694:Gene Products, rev; D015345:Oligonucleotide Probes; D010455:Peptides; D039102:Poly(A)-Binding Proteins; D012333:RNA, Messenger; D012367:RNA, Viral; D016601:RNA-Binding Proteins; D054321:rev Gene Products, Human Immunodeficiency Virus