Abstract
Cross-linking of [125I]helodermin to human SUP-T1 lymphoblasts with bis[2-(succinimidooxycarbonyloxy)ethyl]sulfone (BSOCOES) revealed a 63 K binding protein. This cross-linking was inhibited by helodermin and VIP. In cells submitted for 3-4 days to 0.2 microgram/ml tunicamycin, the Mr of an increasing proportion of helodermin-preferring receptors was reduced to 50 K and the total number of receptors was decreased by about 50%, without alteration in binding affinity and specificity. In parallel, the VIP-mediated adenylate cyclase stimulation was reduced by 30% with no change in NaF-, Gpp[NH]p-, and PGE1-stimulations. We conclude that a proper N-glycosylation of helodermin-preferring VIP receptors is required for normal receptor targeting and turnover but not for ligand binding and adenylate cyclase coupling.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Adenylyl Cyclases / chemistry
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Amino Acid Sequence
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Cell Line
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Cross-Linking Reagents
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Enzyme Activation
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Glycosylation
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Humans
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Intercellular Signaling Peptides and Proteins
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Lymphoma / chemistry*
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Lymphoma / enzymology
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Molecular Sequence Data
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Peptides / chemistry*
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Receptors, Gastrointestinal Hormone / chemistry*
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Receptors, Vasoactive Intestinal Peptide
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Succinimides / chemistry
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Tumor Cells, Cultured
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Vasoactive Intestinal Peptide / chemistry*
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Venoms / chemistry*
Substances
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Cross-Linking Reagents
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Intercellular Signaling Peptides and Proteins
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Peptides
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Receptors, Gastrointestinal Hormone
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Receptors, Vasoactive Intestinal Peptide
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Succinimides
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Venoms
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Vasoactive Intestinal Peptide
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bis(2-(succinimidooxycarbonyloxy)ethyl)sulfone
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heliodermin
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Adenylyl Cyclases