Linked Life Data

13679604

Source:http://linkedlifedata.com/resource/pubmed/id/13679604

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
Pt 10
pubmed:dateCreated
2003-9-18
pubmed:abstractText
The human immunodeficiency virus type 1 (HIV-1) nef gene encodes a 205 residue, myristoylated phosphoprotein that has been shown to play a critical role in the replication and pathogenesis of the virus. One of the most studied functions of the Nef protein is the down-modulation of cell surface CD4. Nef has been reported to interact with both the cytoplasmic tail of CD4 and proteins that are components of the endocytic machinery, thereby enhancing the endocytosis of CD4 through clathrin-coated pits. A di-leucine motif in the cytoplasmic tail of CD4 (residues 413/414) was reported to be essential both for Nef mediated down-modulation and for Nef binding. In order to further characterize the involvement of this di-leucine motif in CD4 down-modulation we generated a CD4 mutant in which the leucines were substituted by alanines, termed CD4(LL-AA). We demonstrate here that, contrary to previous data obtained with the cytoplasmic tail of CD4 alone, full-length CD4(LL-AA) bound to Nef both in vivo, in recombinant baculovirus-infected Sf9 cells, and in vitro. In contrast the di-leucine motif was required for both Nef-mediated and phorbol ester-induced CD4 down-modulation, suggesting that the essential requirement for the di-leucine motif in CD4 down-modulation reflects the fact that this motif is needed for the interactions of CD4 with the endocytic machinery, not for the interaction with Nef. We have also exploited the observation that CD4(LL-AA) is refractory to Nef-mediated down-modulation to provide the first experimental evidence for a physical interaction between Nef and CD4 in intact mammalian cells.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
0022-1317
pubmed:author
pubmed:issnType
Print
pubmed:volume
84
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
2705-13
pubmed:dateRevised
2007-11-15
pubmed:meshHeading
pubmed:year
2003
pubmed:articleTitle
The di-leucine motif in the cytoplasmic tail of CD4 is not required for binding to human immunodeficiency virus type 1 Nef, but is critical for CD4 down-modulation.
pubmed:affiliation
Division of Microbiology, School of Biochemistry and Molecular Biology, University of Leeds, Leeds LS2 9JT, UK.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't