Document Detail


Phosphorylation of the Rex protein of human T-cell leukemia virus type I.
MedLine Citation:
PMID:  1400509     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Rex protein, the posttranscriptional regulator of human T-cell leukemia virus type I (HTLV-I), is required for the control of viral structural protein expression and virus replication. Rex is a phosphoprotein found predominantly in the cell nucleolus, whose function is thought to be regulated by its nucleolar localization and phosphorylation. Therefore, we investigated the in vivo phosphorylation of Rex protein in more detail. Phosphorylation of Rex occurred in all HTLV-I-infected cell lines examined in vivo, primarily at serine residues and to a very small extent at threonine residues. Treatment of cells with 12-O-tetradecanoylphorbol-13-acetate (TPA) led to significant but transient enhancement of the incorporation of [32P]orthophosphate into Rex protein. N-terminal truncation of Rex protein abolished TPA-dependent phosphorylation. Chymotryptic digestion of phosphorylated Rex yielded two phosphopeptides. In vivo phosphorylation sites were identified as serine residues 70 and 177 and threonine residue 174. Serine 70 was a TPA-dependent phosphorylation site within a regulatory domain. We have already shown that the protein kinase C inhibitor H-7 (1-(5-isoquinolinylsulfonyl)-2-methylpiperazine) specifically blocked accumulation of viral unspliced gag-pol mRNA. Therefore, the phosphorylation at serine 70 may be involved in the regulation of Rex function in response to extracellular stimuli.
Authors:
Y Adachi; T D Copeland; C Takahashi; T Nosaka; A Ahmed; S Oroszlan; M Hatanaka
Related Documents :
2303809 - Stimulation of phospholipase d activity by phorbol esters in cultured astrocytes.
1885599 - Role of protein kinase c in catecholamine secretion from digitonin-permeabilized bovine...
12203369 - Enhancement of anchorage-independent growth of human pancreatic carcinoma mia paca-2 ce...
3139319 - Differential effects of diacylglycerols and 12-o-tetradecanoylphorbol-13-acetate on pro...
17673549 - Modulation of nr2b-regulated contextual fear in the hippocampus by the tissue plasminog...
8477649 - Sites of inhibition of steroidogenesis by activation of protein kinase-c in swine ovari...
11044439 - A scaffold protein in the c-jun nh2-terminal kinase signaling pathways suppresses the e...
18262309 - 2,3,5-substituted tetrahydrofurans: cox-2 inhibitory activities of 5-hydroxymethyl-/car...
14992279 - Choline acetyltransferase: regulation and coupling with protein kinase and vesicular ac...
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't; Research Support, U.S. Gov't, P.H.S.    
Journal Detail:
Title:  The Journal of biological chemistry     Volume:  267     ISSN:  0021-9258     ISO Abbreviation:  J. Biol. Chem.     Publication Date:  1992 Oct 
Date Detail:
Created Date:  1992-11-25     Completed Date:  1992-11-25     Revised Date:  2007-11-15    
Medline Journal Info:
Nlm Unique ID:  2985121R     Medline TA:  J Biol Chem     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  21977-81     Citation Subset:  IM; X    
Affiliation:
Institute for Virus Research, Kyoto University, Japan.
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Descriptor/Qualifier:
Amino Acid Sequence
Animals
Blotting, Western
Cell Line
Chromatography, High Pressure Liquid
Down-Regulation
Gene Products, rex / genetics,  metabolism*
Human T-lymphotropic virus 1 / metabolism*
Humans
Molecular Sequence Data
Peptide Mapping
Phosphates / metabolism
Phosphorylation / drug effects
Plasmids
Protein Kinase C / metabolism
Rats
Tetradecanoylphorbol Acetate / pharmacology
Grant Support
ID/Acronym/Agency:
N01-CO-74101/CO/NCI NIH HHS
Chemical
Reg. No./Substance:
0/Gene Products, rex; 0/Phosphates; 16561-29-8/Tetradecanoylphorbol Acetate; EC 2.7.11.13/Protein Kinase C

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


Previous Document:  A missense mutation of L-gulono-gamma-lactone oxidase causes the inability of scurvy-prone osteogeni...
Next Document:  Angiogenin is a cytotoxic, tRNA-specific ribonuclease in the RNase A superfamily.