The heterodimer calmodulin: myosin light-chain kinase as a prototype vertebrate calcium signal transduction complex
| Autor: | D M Watterson, Thomas J. Lukas, Jacques Haiech, Marie-Claude Kilhoffer |
|---|---|
| Rok vydání: | 1992 |
| Předmět: |
animal structures
Myosin light-chain kinase Peptide analog Calmodulin biology Activator (genetics) Protein subunit Molecular Sequence Data Biophysics Biochemistry Cell biology Enzyme Activation Structural Biology biology.protein Calcium Amino Acid Sequence Signal transduction Protein kinase A Cell Adhesion Molecules Myosin-Light-Chain Kinase Sequence Alignment Molecular Biology Peptide sequence Signal Transduction |
| Zdroj: | Biochimica et Biophysica Acta (BBA) - Protein Structure and Molecular Enzymology. 1160:8-15 |
| ISSN: | 0167-4838 |
| DOI: | 10.1016/0167-4838(92)90033-a |
| Popis: | The heterodimer complex of calmodulin (CaM) and the protein kinase catalytic subunit of myosin light chain kinase from vertebrate smooth muscle and non-muscle tissues (sm/nmMLCK) is one of the most extensively characterized CaM-regulated enzyme complexes and it has an established in vivo role in the transduction of calcium signals into biological responses. We have used a combination of approaches to the study of CaM and sm/nmMLCK in order to derive initial insight into the key features of each protein and of the CaM-MLCK heterodimeric complex that are involved in protein-protein and calcium-protein recognition and regulation of enzyme activity. On-going studies are described here that include site-specific mutagenesis, fluorescence spectroscopy, enzymology and peptide analog analysis. These and previous results indicate that: (1), both electrostatic and hydrophobic features are important in the functionally correct interactions between CaM and MLCK; (2), even the interactions between CaM and peptide analogs of the CaM binding site of MLCK are heterogeneous and non-trivial in nature; (3), amino-acid residues that have been conserved in CaM across millions of years of evolution and that are conserved in CaMs with quantitative MLCK activator activity can be mutated without any detectable effect on activity and (4), structures different from the prototypical EF-hand domain of CaM can have similar calcium-binding activity in the presence of a CaM binding structure. |
| Databáze: | OpenAIRE |
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