Electrochemical coupling in the voltage-dependent phosphatase Ci-VSP

TY - JOUR

T1 - Electrochemical coupling in the voltage-dependent phosphatase Ci-VSP

AU - Kohout, Susy C.

AU - Bell, Sarah C.

AU - Liu, Lijun

AU - Xu, Qiang

AU - Minor, Daniel L.

AU - Isacoff, Ehud Y.

N1 - Funding Information: This work was supported by grants R01NS035549 (E.Y.I.), U24NS57631 (E.Y.I.) and R01DC007664 (D.L.M.) from the US National Institutes of Health and by an American Heart Association Established Investigator Award (D.L.M.). We thank Y. Okamura (Japanese National Institute for Physiological Sciences) for kindly providing the Ci-VSP cDNA, T. Meyer (Stanford University) for kindly providing the LDR and CFInp cDNA, E. Reuveny (Weizmann Institute of Science) for providing the IRK1 construct, S. Nakanishi (Osaka Bioscience Institute) for providing the mGluR1α receptor, J. Groves and P. Nair (University of California, Berkeley) for access to and instructions on use of the lipid extruder, and H. Janovjak, K. Nakajo, E. Peled and F. Tombola for helpful discussions.

PY - 2010/5

Y1 - 2010/5

N2 - In the voltage-sensing phosphatase Ci-VSP, a voltage-sensing domain (VSD) controls a lipid phosphatase domain (PD). The mechanism by which the domains are allosterically coupled is not well understood. Using an in vivo assay, we found that the interdomain linker that connects the VSD to the PD is essential for coupling the full-length protein. Biochemical assays showed that the linker is also needed for activity in the isolated PD. We also identified a late step of VSD motion in the full-length protein that depends on the linker. Notably, we found that this VSD motion requires PI(4,5)P 2, a substrate of Ci-VSP. These results suggest that the voltage-driven motion of the VSD turns the enzyme on by rearranging the linker into an activated conformation, and that this activated conformation is stabilized by PI(4,5)P 2. We propose that Ci-VSP activity is self-limited because its decrease of PI(4,5)P 2 levels decouples the VSD from the enzyme.

AB - In the voltage-sensing phosphatase Ci-VSP, a voltage-sensing domain (VSD) controls a lipid phosphatase domain (PD). The mechanism by which the domains are allosterically coupled is not well understood. Using an in vivo assay, we found that the interdomain linker that connects the VSD to the PD is essential for coupling the full-length protein. Biochemical assays showed that the linker is also needed for activity in the isolated PD. We also identified a late step of VSD motion in the full-length protein that depends on the linker. Notably, we found that this VSD motion requires PI(4,5)P 2, a substrate of Ci-VSP. These results suggest that the voltage-driven motion of the VSD turns the enzyme on by rearranging the linker into an activated conformation, and that this activated conformation is stabilized by PI(4,5)P 2. We propose that Ci-VSP activity is self-limited because its decrease of PI(4,5)P 2 levels decouples the VSD from the enzyme.

UR - https://www.scopus.com/pages/publications/77951278810

UR - https://www.scopus.com/pages/publications/77951278810#tab=citedBy

U2 - 10.1038/nchembio.349

DO - 10.1038/nchembio.349

M3 - Article

SN - 1552-4450

VL - 6

SP - 369

EP - 375

JO - Nature Chemical Biology

JF - Nature Chemical Biology

IS - 5

ER -