Journal ArticleDOI
The roles of nucleolar structure and function in the subcellular location of the HIV-1 Rev protein
Miroslav Dundr,Gregory H. Leno,M.-L. Hammarskjold,David Rekosh,C. Helga-Maria,Mark O.J. Olson +5 more
TLDR
The results suggest that the nucleolar location of Rev depends on continuous preribosomal RNA transcription and a substantially intact nucleolar structure.Abstract:
The human immunodeficiency virus 1 (HIV-1) Rev transactivator protein plays a critical role in the regulation of expression of structural proteins by controlling the pathway of mRNA transport. The Rev protein is located predominantly in the nucleoli of HIV-1 infected or Rev-expressing cells. Previous studies demonstrated that the Rev protein forms a specific complex in vitro with protein B23 which is suggested to be a nucleolar receptor and/or carrier for the Rev protein. To study the role of the nucleolus and nucleolar proteins in Rev function, transfected COS-7 or transformed CMT3 cells expressing the Rev protein were examined for subcellular locations of Rev and other proteins using indirect immunofluorescence and immunoelectron microscopy. One day after transfection the Rev protein was found in most cells only in the nucleolar dense fibrillar and granular components where it colocalized with protein B23. These were designated class 1 cells. In a second class of cells Rev and B23 accumulated in the nucleoplasm as well as in nucleoli. Treatment of class 1 cells with actinomycin D (AMD) under conditions that blocked only RNA polymerase I transcription caused Rev to completely redistribute from nucleoli to the cytoplasm. Simultaneously, protein B23 was partially released from nucleoli, mostly into the nucleoplasm, with detectable amounts in the cytoplasm. In cells recovering from AMD treatment in the presence of cycloheximide Rev and B23 showed coincident relocation to nucleoli. Class 2 cells were resistant to AMD-induced Rev redistribution. Selective inhibition of RNA polymerase II transcription by alpha-amanitin or by DRB did not cause Rev to be released into the cytoplasm suggesting that active preribosomal RNA transcription is required for the nucleolar location of Rev. However, treatment with either of the latter two drugs at higher doses and for longer times caused partial disruption of nucleoli accompanied by translocation of the Rev protein to the cytoplasm. These results suggest that the nucleolar location of Rev depends on continuous preribosomal RNA transcription and a substantially intact nucleolar structure.read more
Citations
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Journal ArticleDOI
A Whole-Genome Association Study of Major Determinants for Host Control of HIV-1
Jacques Fellay,Kevin V. Shianna,Dongliang Ge,Sara Colombo,Bruno Ledergerber,Michael E. Weale,Kunlin Zhang,Curtis Gumbs,Antonella Castagna,Andrea Cossarizza,Alessandro Cozzi-Lepri,Andrea De Luca,Philippa Easterbrook,P Francioli,Simon Mallal,Javier Martinez-Picado,José M. Miró,Niels Obel,Jason Smith,Josiane Wyniger,Patrick Descombes,Stylianos E. Antonarakis,Norman L. Letvin,Andrew J. McMichael,Barton F. Haynes,Amalio Telenti,David Goldstein +26 more
TL;DR: Using a whole-genome association strategy, polymorphisms that explain nearly 15% of the variation among individuals in viral load during the asymptomatic set-point period of infection are identified.
Journal ArticleDOI
Deconstructing a Disease: RAR, Its Fusion Partners, and Their Roles in the Pathogenesis of Acute Promyelocytic Leukemia
Ari Melnick,Jonathan D. Licht +1 more
TL;DR: The elucidation of the molecular basis of acute promyelocytic leukemia emerged as a paradigm for the connection between the bench and bedside and it became apparent that APL was, among the forms of acute myeloid leukemia, uniquely sensitive to all
Journal ArticleDOI
The nucleolus: an old factory with unexpected capabilities.
TL;DR: Unexpectedly, the nucleolus also seems to play a role in nuclear export, sequestering regulatory molecules, modifying small RNAs, assembling ribonucleoprotein (RNP) and controlling aging.
Journal ArticleDOI
RNA viruses: hijacking the dynamic nucleolus
TL;DR: Investigating the interactions between RNA viruses and the nucleolus will facilitate the design of novel anti-viral therapies, such as recombinant vaccines and therapeutic molecular interventions, and also contribute to a more detailed understanding of the cell biology of theucleolus.
Journal ArticleDOI
Localization to the Nucleolus Is a Common Feature of Coronavirus Nucleoproteins, and the Protein May Disrupt Host Cell Division
TL;DR: Nucleolar localization signals were identified in the domain III region of the N protein from all three coronavirus groups, and this suggested that transport of N protein to the nucleus might be an active process.
References
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Book ChapterDOI
Use of eukaryotic expression technology in the functional analysis of cloned genes
TL;DR: The purpose of this chapter is to describe ways in which eukaryotic expression technology can be used to identify and to analyze the function of cloned eukARYotic genes.
Journal ArticleDOI
Functional dissection of the HIV-1 Rev trans-activator—Derivation of a trans-dominant repressor of Rev function
TL;DR: Mutation of a second, more C-terminal Rev protein sequence element was found to yield defective Rev proteins that act as trans-dominant inhibitors of Rev function, and these Rev mutants are shown to inhibit HIV-1 replication when expressed in transfected cells and may have potential application in the treatment of AIDS related disease.
Journal ArticleDOI
rev protein of human immunodeficiency virus type 1 affects the stability and transport of the viral mRNA.
Barbara K. Felber,Margarita Hadzopoulou-Cladaras,C Cladaras,Terry D. Copeland,George N. Pavlakis +4 more
TL;DR: The selective effects of rev on the levels of the viral mRNA suggest a model for feedback regulation by rev leading to a steady state of viral expression.
Journal ArticleDOI
Inhibition of RNA synthesis by actinomycin D: characteristic dose-response of different RNA species.
Robert P. Perry,Dawn E. Kelley +1 more
TL;DR: Over the range of actinomycin concentrations employed cellular uptake of the drug is proportional to external concentration, and maximal inhibition of RNA synthesis is generally achieved within one hour after exposure.
Journal ArticleDOI
A vector that replicates as a plasmid and can be efficiently selected in B-lymphoblasts transformed by Epstein-Barr virus.
TL;DR: A vector is constructed that carries oriP and it is shown that it is also efficiently maintained as a plasmid when introduced into EBV-transformed B-lymphoblasts, which makes pHEBo useful for the stable introduction of genes on plasmids intoEBV- transformed lymphoblasts.