Linked Life Data

7589147

Source:http://linkedlifedata.com/resource/pubmed/id/7589147

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
9
pubmed:dateCreated
1995-11-28
pubmed:abstractText
We investigated the effect of extracellular Tat protein of human immunodeficiency virus-type 1 (HIV-1) on the phosphatidylinositol (PI) cycle, which represents a major signal transduction pathway in lymphoid cells. Recombinant Tat, recombinant HIV-1 p24 and cross-linked anti-CD3 monoclonal antibody (mAb) were added in culture for 1-60 min to Jurkat lymphoblastoid CD4+ T cells. The stimulation of T cell receptor by cross-linked anti-CD3 mAb resulted in a rapid increase of the phosphatidylinositol-specific phospholipase C (PI-PLC) activity in whole cell lysates. On the other hand, Tat protein, either alone or in combination with anti-CD3 mAb, showed little effect on the PI turnover of whole cell extracts. Tat, however, selectively stimulated a nuclear-specific PI-PLC with a peak of activity after 30 min from the addition in culture to Jurkat cells. Interestingly, this time corresponded to that required for the uptake and nuclear localization of recombinant Tat protein, as demonstrated by electron microscope immunocytochemistry experiments with anti-Tat mAb. Moreover, exogenous Tat reached the nucleus of Jurkat cells in a bioactive form, as shown in a HIV-1 long terminal repeat-chloramphenicol acetyl transferase transactivation assay. The specific increase of a nuclear PI-PLC activity was further demonstrated by the ability of Tat to stimulate PI turnover also when added directly to isolated nuclei. As a whole, these data demonstrate that Tat selectively stimulates a nuclear polyphosphoinositide hydrolysis, which appears to be independent of the cellular PI turnover. The relevance of these findings for a better understanding of the biological functions of extracellular Tat is discussed.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
0014-2980
pubmed:author
pubmed:issnType
Print
pubmed:volume
25
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
2695-700
pubmed:dateRevised
2007-11-15
pubmed:meshHeading
pubmed:year
1995
pubmed:articleTitle
Exogenous human immunodeficiency virus type-1 Tat protein selectively stimulates a phosphatidylinositol-specific phospholipase C nuclear pathway in the Jurkat T cell line.
pubmed:affiliation
Institute of Human Anatomy, University of Ferrara, Italy.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't