hRIP, a cellular cofactor for Rev function, promotes release of HIV RNAs from the perinuclear region
Graduate School of Biomedical Sciences; Program in Molecular Medicine
Life Sciences | Medicine and Health Sciences
Human immunodeficiency virus Rev facilitates the cytoplasmic accumulation of viral RNAs that contain a Rev binding site. A human Rev-interacting protein (hRIP) was originally identified based on its ability to interact with the Rev nuclear export signal (NES) in yeast two-hybrid assays. To date, however, the function of hRIP and a role for hRIP in Rev-directed RNA export have remained elusive. Here we ablate hRIP activity with a dominant-negative mutant or RNA interference and analyze Rev function by RNA in situ hybridization. We find, unexpectedly, that in the absence of functional hRIP, Rev-directed RNAs mislocalize and aberrantly accumulate at the nuclear periphery, where hRIP is localized. In contrast, in the absence of Rev or the Rev cofactor CRM1, Rev-directed RNAs remain nuclear. We further show that the RNA mislocalization pattern resulting from loss of hRIP activity is highly specific to Rev function: the intracellular distribution of cellular poly(A)(+) mRNA, nuclear proteins, and, most important, NES-containing proteins, are unaffected. Thus, hRIP is an essential cellular Rev cofactor, which acts at a previously unanticipated step in HIV-1 RNA export: movement of RNAs from the nuclear periphery to the cytoplasm.
DOI of Published Version
Genes Dev. 2004 Jan 1;18(1):23-34. Epub 2003 Dec 30. Link to article on publisher's site
Genes and development
Sanchez-Velar, Nuria; Udofia, Enyeneama B.; Yu, Zhong; and Zapp, Maria L., "hRIP, a cellular cofactor for Rev function, promotes release of HIV RNAs from the perinuclear region" (2004). GSBS Student Publications. 1073.