1. A peptide derived from an extracellular domain selectively inhibits receptor internalization: Target sequences on insulin and insulin-like growth factor 1 receptors
- Author
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Tatjana Naranda, Avram Goldstein, and Lennart Olsson
- Subjects
media_common.quotation_subject ,Molecular Sequence Data ,B-cell receptor ,CHO Cells ,Transfection ,Polymerase Chain Reaction ,Receptor, IGF Type 1 ,Growth factor receptor ,Cricetinae ,Adipocytes ,Enzyme-linked receptor ,Animals ,5-HT5A receptor ,Amino Acid Sequence ,Cloning, Molecular ,Internalization ,Protease-activated receptor 2 ,DNA Primers ,Sequence Deletion ,media_common ,Binding Sites ,Multidisciplinary ,Base Sequence ,Sequence Homology, Amino Acid ,biology ,Cell Membrane ,Histocompatibility Antigens Class I ,Exons ,Biological Sciences ,Peptide Fragments ,Receptor, Insulin ,Recombinant Proteins ,Rats ,Insulin receptor ,Glucose ,Biochemistry ,Mutagenesis, Site-Directed ,biology.protein ,Sequence Alignment ,Relaxin/insulin-like family peptide receptor 2 - Abstract
Certain peptides derived from the α1 domain of the major histocompatibility class I antigen complex (MHC-I) inhibit receptor internalization, increasing the steady-state number of active receptors on the cell surface and thereby enhancing the sensitivity to hormones and other agonists. These peptides self-assemble, and they also bind to MHC-I at the same site from which they are derived, suggesting that they could bind to receptor sites with significant sequence similarity. Receptors affected by MHC-I peptides do, indeed, have such sequence similarity, as illustrated here by insulin receptor (IR) and insulin-like growth factor-1 receptor. A synthetic peptide with sequence identical to a certain extracellular receptor domain binds to that receptor in a ligand-dependent manner and inhibits receptor internalization. Moreover, each such peptide is selective for its cognate receptor. An antibody to the IR peptide not only binds to IR and competes with the peptide but also inhibits insulin-dependent internalization of IR. These observations, and binding studies with deletion mutants of IR, indicate that the sequence QILKELEESSF encoded by exon 10 plays a key role in IR internalization. Our results illustrate a principle for identifying receptor-specific sites of importance for receptor internalization, and for enhancing sensitivity to hormones and other agonists.
- Published
- 1997
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