Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0021051 (immunodeficiency)
 71,517 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The Rev protein of human immunodeficiency virus type 1 (HIV-1) facilitates the nuclear export of unspliced and partly spliced viral RNAs. Rev contains an RNA binding domain, required for interaction with HIV-1 RNA, and an effector domain, required for RNA-bound Rev to function. The Rev effector domain is believed to interact with a cellular cofactor required for the Rev response and thus HIV-1 replication. Here we report the use of a yeast two-hybrid screen to clone human Rev interacting protein (hRIP), which specifically interacts with the Rev effector domain. This hRIP protein has homology with nucleoporins, a class of proteins that mediate nucleocytoplasmic transport. These and other properties of hRIP are those expected of a Rev cellular cofactor.
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PMID:A human nucleoporin-like protein that specifically interacts with HIV Rev. 763 88

Using a two-hybrid screening with TOM1, a putative ubiquitin-ligase gene of Saccharomyces cerevisiae, we isolated KRR1, a homologue of human HRB2 (for human immunodeficiency virus type 1 Rev-binding protein 2). To characterize the gene function, we constructed temperature-sensitive krr1 mutants and isolated two multicopy suppressors. One suppressor is RPS14A, encoding a 40S ribosomal protein. The C-terminal-truncated rpS14p, which was reported to have diminished binding activity to 18S rRNA, failed to suppress the krr1 mutant. The other suppressor is a novel gene, KRI1 (for KRR1 interacting protein; YNL308c). KRI1 is essential for viability, and Kri1p is localized to the nucleolus. We constructed a galactose-dependent kri1 strain by placing KRI1 under control of the GAL1 promoter, so that expression of KRI1 was shut off when transferring the culture to glucose medium. Polysome and 40S ribosome fractions were severely decreased in the krr1 mutant and Kri1p-depleted cells. Pulse-chase analysis of newly synthesized rRNAs demonstrated that 18S rRNA is not produced in either mutant. However, wild-type levels of 25S rRNA are made in either mutant. Northern analysis revealed that the steady-state levels of 18S rRNA and 20S pre-rRNAs were reduced in both mutants. Precursors for 18S rRNA were detected but probably very unstable in both mutants. A myc-tagged Kri1p coimmunoprecipitated with a hemagglutinin-tagged Krr1p. Furthermore, the krr1 mutant protein was defective in its interaction with Kri1p. These data lead us to conclude that Krr1p physically and functionally interacts with Kri1p to form a complex which is required for 40S ribosome biogenesis in the nucleolus.
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PMID:Yeast Krr1p physically and functionally interacts with a novel essential Kri1p, and both proteins are required for 40S ribosome biogenesis in the nucleolus. 1102 67