Linked Life Data

15494497

Source:http://linkedlifedata.com/resource/pubmed/id/15494497

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
9
pubmed:dateCreated
2004-10-20
pubmed:abstractText
HIV Nef down-regulates CD4 from the cell surface in the absence of CD4 phosphorylation, whereas PMA down-regulates CD4 through a phosphorylation-dependent pathway. In this study we show that the down-regulation of CD4 in human Jurkat T cells expressing Nef was nearly complete (approximately 95%), whereas that induced by PMA was partial (approximately 40%). Unexpectedly, treating T cells expressing Nef with PMA restored the surface CD4 up to 35% of the steady state level. Both mutating the phosphorylation sites in the CD4 cytoplasmic tail (Ser408 and Ser415) and the use of a protein kinase C inhibitor, bisindolylmaleimide1, abolished the restoration of surface CD4, suggesting that the restoration required CD4 phosphorylation. CD4 and Nef could be cross-linked by a chemical cross-linker, 3,3-dithiobis[sulfosuccinimidyl-propionate], in control T cell membranes, but not in PMA-treated T cell membrane, suggesting that CD4 and Nef interacted with each other in T cells, and the phosphorylation disrupted the CD4-Nef interaction. We propose that this dissociation switches CD4 internalization from the Nef-mediated, nearly complete down-regulation to a phosphorylation-dependent, partial down-regulation, resulting in a net gain of CD4 on the T cell surface.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
AIM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
0022-1767
pubmed:author
pubmed:issnType
Print
pubmed:day
1
pubmed:volume
173
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
5495-500
pubmed:dateRevised
2007-11-15
pubmed:meshHeading
pubmed:year
2004
pubmed:articleTitle
CD4 phosphorylation partially reverses Nef down-regulation of CD4.
pubmed:affiliation
Skirball Institute of Biomedical Research, New York University School of Medicine, New York, NY 10016, USA. jiny@saturn.med.nyu.edu
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't