Open Access. Powered by Scholars. Published by Universities.®
- Keyword
-
- Animals (2)
- Humans (2)
- Phosphoric Monoester Hydrolases (2)
- Xenopus (2)
- 310 helix (1)
-
- CHO Cells (1)
- Ci-VSP (1)
- Cricetinae (1)
- Electrophysiology (1)
- Fluorescence (1)
- Genes (1)
- Genes, Reporter (1)
- Ion Channel Gating (1)
- Kinetics (1)
- Kv1.2 Potassium Channel (1)
- Membrane Potentials (1)
- Microscopy (1)
- Microscopy, Fluorescence (1)
- Missense (1)
- Molecular Dynamics Simulation (1)
- Mutation (1)
- Mutation, Missense (1)
- Oocytes (1)
- Phosphatidylinositols (1)
- Potassium (1)
- Protein Structure (1)
- Protein Structure, Tertiary (1)
- Reporter (1)
- Sensing current (1)
- Signal Transduction (1)
Articles 1 - 3 of 3
Full-Text Articles in Medicine and Health Sciences
Molecular Mechanism For Depolarization-Induced Modulation Of Kv Channel Closure, Alain J. Labro, Jerome J. Lacroix, Carlos A. Villalba-Galea, Dirk J. Snyders, Francisco Bezanilla
Molecular Mechanism For Depolarization-Induced Modulation Of Kv Channel Closure, Alain J. Labro, Jerome J. Lacroix, Carlos A. Villalba-Galea, Dirk J. Snyders, Francisco Bezanilla
School of Pharmacy Faculty Articles
Voltage-dependent potassium (Kv) channels provide the repolarizing power that shapes the action potential duration and helps control the firing frequency of neurons. The K(+) permeation through the channel pore is controlled by an intracellularly located bundle-crossing (BC) gate that communicates with the voltage-sensing domains (VSDs). During prolonged membrane depolarizations, most Kv channels display C-type inactivation that halts K(+) conduction through constriction of the K(+) selectivity filter. Besides triggering C-type inactivation, we show that in Shaker and Kv1.2 channels (expressed in Xenopus laevis oocytes), prolonged membrane depolarizations also slow down the kinetics of VSD deactivation and BC gate closure during the …
A Human Phospholipid Phosphatase Activated By A Transmembrane Control Module, Christian R. Halaszovich, Michael G. Leitner, Angeliki Mavrantoni, Audrey Le, Ludivine Frezza, Anja Feuer, Daniela N. Schreiber, Carlos A. Villalba-Galea, Dominik Oliver
A Human Phospholipid Phosphatase Activated By A Transmembrane Control Module, Christian R. Halaszovich, Michael G. Leitner, Angeliki Mavrantoni, Audrey Le, Ludivine Frezza, Anja Feuer, Daniela N. Schreiber, Carlos A. Villalba-Galea, Dominik Oliver
School of Pharmacy Faculty Articles
In voltage-sensitive phosphatases (VSPs), a transmembrane voltage sensor domain (VSD) controls an intracellular phosphoinositide phosphatase domain, thereby enabling immediate initiation of intracellular signals by membrane depolarization. The existence of such a mechanism in mammals has remained elusive, despite the presence of VSP-homologous proteins in mammalian cells, in particular in sperm precursor cells. Here we demonstrate activation of a human VSP (hVSP1/TPIP) by an intramolecular switch. By engineering a chimeric hVSP1 with enhanced plasma membrane targeting containing the VSD of a prototypic invertebrate VSP, we show that hVSP1 is a phosphoinositide-5-phosphatase whose predominant substrate is PI(4,5)P(2). In the chimera, enzymatic activity …
Voltage-Controlled Enzymes: The New Janus Bifrons, Carlos A. Villalba-Galea
Voltage-Controlled Enzymes: The New Janus Bifrons, Carlos A. Villalba-Galea
School of Pharmacy Faculty Articles
The Ciona intestinalis voltage-sensitive phosphatase, Ci-VSP, was the first Voltage-controlled Enzyme (VEnz) proven to be under direct command of the membrane potential. The discovery of Ci-VSP conjugated voltage sensitivity and enzymatic activity in a single protein. These two facets of Ci-VSP activity have provided a unique model for studying how membrane potential is sensed by proteins and a novel mechanism for control of enzymatic activity. These facets make Ci-VSP a fascinating and versatile enzyme. Ci-VSP has a voltage sensing domain (VSD) that resembles those found in voltage-gated channels (VGC). The VSD resides in the N-terminus and is formed by four …