Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
1993-9-8
pubmed:databankReference
pubmed:abstractText
Merosin is a 700 kDa multichain protein that has several properties in common with laminin, one of the major extracellular matrix proteins present in basement membranes. Both contain B1 and B2 light chains, but merosin has a distinct M-chain compared with the laminin A-chain. Merosin is present in the basement membrane of placenta, striated muscle, and peripheral nerve. Using the RT-PCR assay, we demonstrate that merosin, but not laminin, is also expressed in the thymus. A partial cDNA sequence of the mouse merosin M-chain was 88% identical to the human M-chain, and the deduced amino acid sequences were 95% identical. 18-24% of adult mouse thymocytes bound to human merosin in vitro. Mg2+, but not Ca2+, was essential for binding. Binding was inhibited by antibodies recognizing VLA alpha 6 or beta 1, suggesting that the VLA-6 integrin is a merosin receptor. An anti-beta 4 integrin subunit mAb failed to inhibit binding, suggesting that the alpha 6 beta 4 integrin was not involved. Thymocytes were fractionated into immature and mature populations based on their expression of the heat stable antigen, recognized by the J11d mAb. Virtually all thymocytes expressed VLA-6, but only immature thymocytes (J11d+) bound to meroson. PMA treatment did not significantly increase the binding of J11d+ thymocytes nor did induce binding in the mature J11d- population. In constrast, both splenic T cells and unseparated lymph node cells showed enhanced binding to merosin after PMA stimulation. The expression of merosin in the thymus and its selective interaction with immature thymocytes suggest that thymocyte-merosin interactions may play a role in T cell development.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
AIM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0022-1767
pubmed:author
pubmed:issnType
Print
pubmed:day
15
pubmed:volume
151
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1789-801
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed-meshheading:8345183-Amino Acid Sequence, pubmed-meshheading:8345183-Animals, pubmed-meshheading:8345183-Base Sequence, pubmed-meshheading:8345183-Calcium, pubmed-meshheading:8345183-Cell Adhesion, pubmed-meshheading:8345183-Extracellular Matrix Proteins, pubmed-meshheading:8345183-Female, pubmed-meshheading:8345183-Humans, pubmed-meshheading:8345183-Magnesium, pubmed-meshheading:8345183-Membrane Proteins, pubmed-meshheading:8345183-Mice, pubmed-meshheading:8345183-Mice, Inbred C57BL, pubmed-meshheading:8345183-Molecular Sequence Data, pubmed-meshheading:8345183-Oligodeoxyribonucleotides, pubmed-meshheading:8345183-RNA, Messenger, pubmed-meshheading:8345183-Receptors, Very Late Antigen, pubmed-meshheading:8345183-Sequence Alignment, pubmed-meshheading:8345183-Sequence Homology, Amino Acid, pubmed-meshheading:8345183-Thymus Gland
pubmed:year
1993
pubmed:articleTitle
Expression of merosin in the thymus and its interaction with thymocytes.
pubmed:affiliation
Biological Resources Branch, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892.
pubmed:publicationType
Journal Article, Comparative Study