Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:2.1.1.148 (Thy1)
 1,210 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Caveolae are plasma membrane invaginations, which have been implicated in endothelial transcytosis, endocytosis, potocytosis, and signal transduction. In addition to their well-defined morphology, caveolae are characterized by the presence of an integral membrane protein termed VIP21-caveolin. We have recently observed that lymphocytes have no detectable VIP21-caveolin and lack plasma membrane invaginations resembling caveolae. Here we transiently express VIP21-caveolin in a lymphocyte cell line using the Semliki Forest virus expression system and show de novo formation of plasma membrane invaginations containing VIP21-caveolin. These invaginations appear homogeneous in size and morphologically indistinguishable from caveolae of nonlymphoid cells. Moreover, the glycosylphosphatidylinositol-anchored protein. Thy1, patched by antibodies, redistributes to the newly formed caveolae. Our results show that VIP21-caveolin is a key structural component required for caveolar biogenesis.
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PMID:De novo formation of caveolae in lymphocytes by expression of VIP21-caveolin. 756 92

Antibody binding to glycolipids and glycophosphatidylinositol (GPI)-anchored proteins of lymphocytes can trigger activation of specific signal transduction pathways. The finding that GPI-anchored proteins are present in detergent-insoluble complexes with several tyrosine kinases of the Src family suggested that these complexes may represent membrane microdomains involved in the transduction of signals to the cell interior. Recent work has suggested a link between detergent-insoluble microdomains and plasma membrane invaginations termed caveolae. Here we show that lymphocytes lack plasma membrane domains with the characteristic features of caveolae. Furthermore, VIP21-caveolin was not detectable in four different lymphocyte cell lines at the protein or mRNA level. In addition to the lack of caveolar domains, capping experiments suggested that the bulk of the GPI-anchored protein Thy1 and the glycosphingolipid GM1 were not stably associated in the lymphocyte plasma membrane. Despite this, Thy1 and GM1 were present in detergent-insoluble complexes. We conclude that detergent insolubility does not correlate with the presence of caveolae or of VIP21-caveolin and that caveolae, as defined by a number of different markers, are not involved in signal transduction in lymphocytes.
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PMID:Detergent-insoluble glycolipid microdomains in lymphocytes in the absence of caveolae. 798 98