PUBLICATION

Engineering an enhanced voltage-sensing phosphatase

Authors
Kawanabe, A., Mizutani, N., Polat, O.K., Yonezawa, T., Kawai, T., Mori, M.X., Okamura, Y.
ID
ZDB-PUB-200403-57
Date
2020
Source
The Journal of general physiology   152(5): (Journal)
Registered Authors
Kawai, Takafumi, Okamura, Yasushi
Keywords
none
MeSH Terms
  • Animals
  • Cell Line
  • Cytoplasm/metabolism
  • HEK293 Cells
  • Humans
  • Mammals/metabolism
  • Membrane Potentials/physiology*
  • Phosphatidylinositol 4,5-Diphosphate/metabolism
  • Phosphoric Monoester Hydrolases/metabolism*
  • Potassium Channels, Voltage-Gated/metabolism
  • TRPC6 Cation Channel/metabolism
PubMed
32167537 Full text @ J. Gen. Physiol.
Abstract
Voltage-sensing phosphatases (VSP) consist of a membrane-spanning voltage sensor domain and a cytoplasmic region that has enzymatic activity toward phosphoinositides (PIs). VSP enzyme activity is regulated by membrane potential, and its activation leads to rapid and reversible alteration of cellular PIP levels. These properties enable VSPs to be used as a tool for studying the effects of phosphatidylinositol-4,5-bisphosphate (PI(4,5)P2) binding to ion channels and transporters. For example, by applying simple changes in the membrane potential, Danio rerio VSP (Dr-VSP) has been used effectively to manipulate PI(4,5)P2 in mammalian cells with few, if any, side effects. In the present study, we report an enhanced version of Dr-VSP as an improved molecular tool for depleting PI(4,5)P2 from cultured mammalian cells. We modified Dr-VSP in two ways. Its voltage-dependent phosphatase activity was enhanced by introducing an aromatic residue at the position of Leu-223 within a membrane-interacting region of the phosphatase domain called the hydrophobic spine. In addition, selective plasma membrane targeting of Dr-VSP was facilitated by fusion with the N-terminal region of Ciona intestinalis VSP. This modified Dr-VSP (CiDr-VSPmChe L223F, or what we call eVSP) induced more drastic voltage-evoked changes in PI(4,5)P2 levels, using the activities of Kir2.1, KCNQ2/3, and TRPC6 channels as functional readouts. eVSP is thus an improved molecular tool for evaluating the PI(4,5)P2 sensitivity of ion channels in living cells.
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