TY - JOUR
T1 - Dimerization of the voltage-sensing phosphatase controls its voltage-sensing and catalytic activity
AU - Rayaprolu, Vamseedhar
AU - Royal, Perrine
AU - Stengel, Karen
AU - Sandoz, Guillaume
AU - Kohout, Susy C.
N1 - Funding Information:
We thank Y. Okamura for providing the Ci-VSP cDNA, E.Y. Isacoff for the fPLC and fTAPP, and E. Lingueglia for ASIC1A. This work was supported by start-up funds from the Vice President for Research, Creativity and Technology Transfer at Montana State University (S.C. Kohout); National Institute of General Medical Science of the National Institutes of Health grants R01GM111685 (S.C. Kohout) and P20GM103474 (K. Stengel); Fondation pour la Recherche Médicale Equipe FRM grant DEQ20170336753 (G. Sandoz); ATIP-AVE NIR grants (G. Sandoz); and Fondation NRJ-Institut de France and Agence Nationale de la Recherche (Laboratory of Excellence "Ion Channel Science and Therapeutics" grant ANR-11LABX-0015-01).
Funding Information:
We thank Y. Okamura for providing the Ci-VSP cDNA, E.Y. Isacoff for the fPLC and fTAPP, and E. Lingueglia for ASIC1A. This work was supported by start-up funds from the Vice President for Research, Creativity and Technology Transfer at Montana State University (S.C. Kohout); National Institute of General Medical Science of the National Institutes of Health grants R01GM111685 (S.C. Kohout) and P20GM103474 (K. Stengel); Fondation pour la Recherche M?dicale Equipe FRM grant DEQ20170336753 (G. Sandoz); ATIP-AVE NIR grants (G. Sandoz); and Fondation NRJ-Institut de France and Agence Nationale de la Recherche (Laboratory of Excellence "Ion Channel Science and Therapeutics" grant ANR-11LABX-0015-01).
Publisher Copyright:
© 2018 Rayaprolu et al.
PY - 2018/5/1
Y1 - 2018/5/1
N2 - 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.
AB - 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.
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U2 - 10.1085/jgp.201812064
DO - 10.1085/jgp.201812064
M3 - Article
C2 - 29695412
AN - SCOPUS:85046741465
SN - 0022-1295
VL - 150
SP - 683
EP - 696
JO - Journal of General Physiology
JF - Journal of General Physiology
IS - 5
ER -