Voltage-gated L-type Cav1.2 calcium channels couple membrane depolarization to transient increase in cytoplasmic free Ca(2+) concentration that initiates a number of essential cellular functions including cardiac and vascular muscle contraction, gene expression, neuronal plasticity, and exocytosis. Inactivation or spontaneous termination of the calcium current through Cav1.2 is a critical step in regulation of these processes. The pathophysiological significance of this process is manifested in hypertension, heart failure, arrhythmia, and a number of other diseases where acceleration of the calcium current decay should present a benefit function. The central issue of this paper is the inactivation of the Cav1.2 calcium channel mediated by multiple determinants.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4890872 | PMC |
http://dx.doi.org/10.5402/2012/691341 | DOI Listing |
J Biol Chem
April 2022
Department of Biology, University of Toronto Mississauga, Mississauga, Ontario, Canada. Electronic address:
Ca1 and Ca2 voltage-gated calcium channels evolved from an ancestral Ca1/2 channel via gene duplication somewhere near the stem animal lineage. The divergence of these channel types led to distinguishing functional properties that are conserved among vertebrates and bilaterian invertebrates and contribute to their unique cellular roles. One key difference pertains to their regulation by calmodulin (CaM), wherein bilaterian Ca1 channels are uniquely subject to pronounced, buffer-resistant Ca/CaM-dependent inactivation, permitting negative feedback regulation of calcium influx in response to local cytoplasmic Ca rises.
View Article and Find Full Text PDFJ Biol Chem
December 2020
Department of Biology, University of Toronto Mississauga, Mississauga, Ontario, Canada. Electronic address:
The dominant role of Ca2 voltage-gated calcium channels for driving neurotransmitter release is broadly conserved. Given the overlapping functional properties of Ca2 and Ca1 channels, and less so Ca3 channels, it is unclear why there have not been major shifts toward dependence on other Ca channels for synaptic transmission. Here, we provide a structural and functional profile of the Ca2 channel cloned from the early-diverging animal , which lacks a nervous system but possesses single gene homologues for Ca1-Ca3 channels.
View Article and Find Full Text PDFJ Biol Chem
October 2020
Department of Physiology and Cellular Biophysics, Columbia University, New York, New York, USA. Electronic address:
Calmodulin (CaM) regulation of voltage-gated calcium (Ca1-2) channels is a powerful Ca-feedback mechanism to adjust channel activity in response to Ca influx. Despite progress in resolving mechanisms of CaM-Ca feedback, the stoichiometry of CaM interaction with Ca channels remains ambiguous. Functional studies that tethered CaM to Ca1.
View Article and Find Full Text PDFJ Gen Physiol
June 2014
Calcium Signals Laboratory, Department of Biomedical Engineering, Department of Neuroscience, and Center for Cell Dynamics, Johns Hopkins University School of Medicine, Baltimore, MD 21205Calcium Signals Laboratory, Department of Biomedical Engineering, Department of Neuroscience, and Center for Cell Dynamics, Johns Hopkins University School of Medicine, Baltimore, MD 21205Calcium Signals Laboratory, Department of Biomedical Engineering, Department of Neuroscience, and Center for Cell Dynamics, Johns Hopkins University School of Medicine, Baltimore, MD 21205Calcium Signals Laboratory, Department of Biomedical Engineering, Department of Neuroscience, and Center for Cell Dynamics, Johns Hopkins University School of Medicine, Baltimore, MD 21205
Calmodulin regulation (calmodulation) of the family of voltage-gated CaV1-2 channels comprises a prominent prototype for ion channel regulation, remarkable for its powerful Ca(2+) sensing capabilities, deep in elegant mechanistic lessons, and rich in biological and therapeutic implications. This field thereby resides squarely at the epicenter of Ca(2+) signaling biology, ion channel biophysics, and therapeutic advance. This review summarizes the historical development of ideas in this field, the scope and richly patterned organization of Ca(2+) feedback behaviors encompassed by this system, and the long-standing challenges and recent developments in discerning a molecular basis for calmodulation.
View Article and Find Full Text PDFJ Physiol
May 2010
Department of Physiology and Cellular Biophysics, Columbia University, College of Physicians and Surgeons, New York, NY 10032, USA.
Rad/Rem/Gem/Kir (RGK) GTPases potently inhibit Ca(V)1 and Ca(V)2 (Ca(V)1-2) channels, a paradigm of ion channel regulation by monomeric G-proteins with significant physiological ramifications and potential biotechnology applications. The mechanism(s) underlying how RGK proteins inhibit I(Ca) is unknown, and it is unclear how key structural and regulatory properties of these GTPases (such as the role of GTP binding to the nucleotide binding domain (NBD), and the C-terminus which contains a membrane-targeting motif) feature in this effect. Here, we show that Rem inhibits Ca(V)1.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!