Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
17
pubmed:dateCreated
2011-4-25
pubmed:abstractText
Cell surface proteoglycans on T cells contribute to retroviral infection, binding of chemokines and other proteins, and are necessary for some T cell responses to the matricellular glycoprotein thrombospondin-1. The major cell surface proteoglycans expressed by primary T cells and Jurkat T cells have an apparent M(r) > 200,000 and are modified with chondroitin sulfate and heparan sulfate chains. Thrombospondin-1 bound in a heparin-inhibitable manner to this proteoglycan and to a soluble form released into the medium. Based on mass spectrometry, knockdown, and immunochemical analyses, the proteoglycan contains two major core proteins as follows: amyloid precursor-like protein-2 (APLP2, apparent M(r) 230,000) and CD47 (apparent M(r) > 250,000). CD47 is a known thrombospondin-1 receptor but was not previously reported to be a proteoglycan. This proteoglycan isoform of CD47 is widely expressed on vascular cells. Mutagenesis identified glycosaminoglycan modification of CD47 at Ser(64) and Ser(79). Inhibition of T cell receptor signaling by thrombospondin-1 was lost in CD47-deficient T cells that express the proteoglycan isoform of APLP2, indicating that binding to APLP2 is not sufficient. Inhibition of CD69 induction was restored in CD47-deficient cells by re-expressing CD47 or an S79A mutant but not by the S64A mutant. Therefore, inhibition of T cell receptor signaling by thrombospondin-1 is mediated by CD47 and requires its modification at Ser(64).
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
1083-351X
pubmed:author
pubmed:issnType
Electronic
pubmed:day
29
pubmed:volume
286
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
14991-5002
pubmed:meshHeading
pubmed:year
2011
pubmed:articleTitle
Heparan sulfate modification of the transmembrane receptor CD47 is necessary for inhibition of T cell receptor signaling by thrombospondin-1.
pubmed:affiliation
Laboratory of Pathology, Center for Cancer Research, NCI, National Institutes of Health, Bethesda, Maryland 20982, USA.
pubmed:publicationType
Journal Article, Research Support, N.I.H., Intramural