Document Type
Article
Version Deposited
Published Version
Publication Date
2-4-2019
Publication Title
The Journal of general physiology
DOI
10.1085/jgp.201812260
Abstract
Voltage-sensing phosphatases (VSPs) cleave both 3- and 5-phosphates from inositol phospholipids in response to membrane depolarization. When low concentrations of Ciona intestinalis VSP are expressed in Xenopus laevis oocytes, the 5-phosphatase reaction can be observed during large membrane depolarizations. When higher concentrations are expressed, the 5-phosphatase activity is observed with smaller depolarizations, and the 3-phosphatase activity is revealed with strong depolarization. Here we ask whether this apparent induction of 3-phosphatase activity is attributable to the dimerization that has been reported when VSP is expressed at higher concentrations. Using a simple kinetic model, we show that these enzymatic phenomena can be understood as an emergent property of a voltage-dependent enzyme with invariant substrate selectivity operating in the context of endogenous lipid-metabolizing enzymes present in oocytes. Thus, a switch of substrate specificity with dimerization need not be invoked to explain the appearance of 3-phosphatase activity at high VSP concentrations.
Recommended Citation
Kruse, Martin; Kohout, Susy C; and Hille, Bertil, "Reinterpretation of the substrate specificity of the voltage-sensing phosphatase during dimerization." (2019). Cooper Medical School of Rowan University Faculty Scholarship. 10.
https://rdw.rowan.edu/cmsru_facpub/10
Creative Commons License
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Published Citation
Citation
Martin Kruse, Susy C. Kohout, Bertil Hille; Reinterpretation of the substrate specificity of the voltage-sensing phosphatase during dimerization. J Gen Physiol 4 February 2019; 151 (2): 258–263. doi: https://doi.org/10.1085/jgp.201812260
Comments
Article published after 6-month embargo as required by publisher.