Ion Channel Clustering by Membrane-associated Guanylate Kinases
| Autor: | Sarah E. Craven, Alaa El-Husseini, Chiye Aoki, Joshua E. Lehrer-Graiwer, J. Rick Topinka, Bonnie L. Firestein, David S. Bredt |
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| Rok vydání: | 2000 |
| Předmět: |
genetic structures
Guanylate kinase musculoskeletal neural and ocular physiology Cell Biology Hippocampal formation Biology Biochemistry Cell biology N-terminus nervous system Palmitoylation Postsynaptic potential mental disorders Signal transduction Molecular Biology Postsynaptic density psychological phenomena and processes Ion channel |
| Zdroj: | Journal of Biological Chemistry. 275:23904-23910 |
| ISSN: | 0021-9258 |
| DOI: | 10.1074/jbc.m909919199 |
| Popis: | The postsynaptic density protein PSD-95 and related membrane-associated guanylate kinase (MAGUK) proteins assemble signal transduction complexes at sites of cell-cell contact including synapses. Whereas PSD-95 and PSD-93 occur only at postsynaptic sites in hippocampal neurons, SAP-102 also occurs in axons. In heterologous cells, PSD-95 and PSD-93 mediate cell surface ion channel clustering, but SAP-102 and SAP-97 do not. This selective ion channel clustering activity by MAGUKs is explained by differential palmitoylation, as PSD-93 and PSD-95 are palmitoylated though SAP-97, and SAP-102 are not. Rather than being palmitoylated, we find that N-terminal cysteines from SAP-102 tightly bind to zinc. And, appending the N terminus of SAP-102 to PSD-95 results in localization of the chimera to both axons and dendrites. These data suggest that lipid modifications and heavy metal associations with the N termini of MAGUKs mediate differential functions and subcellular localizations of these synaptic scaffolds. |
| Databáze: | OpenAIRE |
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