N-terminus-mediated dimerization of ROCK-I is required for RhoE binding and actin reorganization
| Autor: | Nicholas H. Keep, Jonathan D.H. Morris, Ritu Garg, Anne J. Ridley, Kirsi Riento |
|---|---|
| Rok vydání: | 2008 |
| Předmět: |
rho GTP-Binding Proteins
rho-Associated Kinases RHOA Kinase Cell Biology Plasma protein binding Biology Actin cytoskeleton Biochemistry Actins Cell biology Protein kinase domain COS Cells Chlorocebus aethiops biology.protein Animals Phosphorylation Kinase activity Dimerization Molecular Biology Cytoskeleton Actin Protein Binding |
| Zdroj: | Biochemical Journal. 411:407-414 |
| ISSN: | 1470-8728 0264-6021 |
| DOI: | 10.1042/bj20071342 |
| Popis: | ROCK-I (Rho-associated kinase 1) is a serine/threonine kinase that can be activated by RhoA and inhibited by RhoE. ROCK-I has an N-terminal kinase domain, a central coiled-coil region and a RhoA-binding domain near the C-terminus. We have previously shown that RhoE binds to the N-terminal 420 amino acids of ROCK-I, which includes the kinase domain as well as N-terminal and C-terminal extensions. In the present study, we show that N-terminus-mediated dimerization of ROCK-I is required for RhoE binding. The central coiled-coil domain can also dimerize ROCK-I in cells, but this is insufficient in the absence of the N-terminus to allow RhoE binding. The kinase activity of ROCK-I1–420 is required for dimerization and RhoE binding; however, inclusion of part of the coiled-coil domain compensates for lack of kinase activity, allowing RhoE to bind. N-terminus-mediated dimerization is also required for ROCK-I to induce the formation of stellate actin stress fibres in cells. These results indicate that dimerization via the N-terminus is critical for ROCK-I function in cells and for its regulation by RhoE. |
| Databáze: | OpenAIRE |
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