Dimerization of the voltage-sensing phosphatase controls its voltage-sensing and catalytic activity
| Autor: | Susy C. Kohout, Guillaume Sandoz, Vamseedhar Rayaprolu, Karen Stengel, Perrine Royal |
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| Rok vydání: | 2018 |
| Předmět: |
0301 basic medicine
Phosphoric monoester hydrolases Physiology Immunoprecipitation Xenopus Phosphatase Phosphatidylinositols Fluorescence spectroscopy Membrane Potentials 03 medical and health sciences chemistry.chemical_compound 0302 clinical medicine Phosphatidylinositol Phosphates Catalytic Domain Pi Animals Humans Ciona intestinalis Research Articles biology Chemistry biology.organism_classification Phosphoric Monoester Hydrolases HEK293 Cells 030104 developmental biology Monomer Biophysics Protein Multimerization 030217 neurology & neurosurgery Function (biology) Research Article |
| Zdroj: | The Journal of General Physiology |
| ISSN: | 1540-7748 0022-1295 |
| DOI: | 10.1085/jgp.201812064 |
| Popis: | The Ciona intestinalis voltage-sensing phosphatase (Ci-VSP) was not thought to multimerize. Rayaprolu et al. show that Ci-VSP exists as a dimer and that this interaction lowers the voltage dependence of activation and alters substrate specificity. Multimerization is a key characteristic of most voltage-sensing proteins. The main exception was thought to be the Ciona intestinalis voltage-sensing phosphatase (Ci-VSP). In this study, we show that multimerization is also critical for Ci-VSP function. Using coimmunoprecipitation and single-molecule pull-down, we find that Ci-VSP stoichiometry is flexible. It exists as both monomers and dimers, with dimers favored at higher concentrations. We show strong dimerization via the voltage-sensing domain (VSD) and weak dimerization via the phosphatase domain. Using voltage-clamp fluorometry, we also find that VSDs cooperate to lower the voltage dependence of activation, thus favoring the activation of Ci-VSP. Finally, using activity assays, we find that dimerization alters Ci-VSP substrate specificity such that only dimeric Ci-VSP is able to dephosphorylate the 3-phosphate from PI(3,4,5)P3 or PI(3,4)P2. Our results indicate that dimerization plays a significant role in Ci-VSP function. |
| Databáze: | OpenAIRE |
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