Demonstration of Binding of Neuronal Calcium Sensor-1 to the Ca_v2.1 P/Q-Type Calcium Channel

Lian, Lu-Yun, Pandalaneni, Sravan R, Todd, Paul AC, Martin, Victoria M, Burgoyne, Robert D ORCID: 0000-0002-9219-0387 and Haynes, Lee P ORCID: 0000-0002-1296-0338 (2014) Demonstration of Binding of Neuronal Calcium Sensor-1 to the Ca_v2.1 P/Q-Type Calcium Channel. BIOCHEMISTRY, 53 (38). pp. 6052-6062.

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Abstract

In neurons, entry of extracellular calcium (Ca(2+)) into synaptic terminals through Cav2.1 (P/Q-type) Ca(2+) channels is the driving force for exocytosis of neurotransmitter-containing synaptic vesicles. This class of Ca(2+) channel is, therefore, pivotal during normal neurotransmission in higher organisms. In response to channel opening and Ca(2+) influx, specific Ca(2+)-binding proteins associate with cytoplasmic regulatory domains of the P/Q channel to modulate subsequent channel opening. Channel modulation in this way influences synaptic plasticity with consequences for higher-level processes such as learning and memory acquisition. The ubiquitous Ca(2+)-sensing protein calmodulin (CaM) regulates the activity of all types of mammalian voltage-gated Ca(2+) channels, including the P/Q class, by direct binding to specific regulatory motifs. More recently, experimental evidence has highlighted a role for additional Ca(2+)-binding proteins, particularly of the CaBP and NCS families in the regulation of P/Q channels. NCS-1 is a protein found from yeast to humans and that regulates a diverse number of cellular functions. Physiological and genetic evidence indicates that NCS-1 regulates P/Q channel activity, including calcium-dependent facilitation, although a direct physical association between the proteins has yet to be demonstrated. In this study, we aimed to determine if there is a direct interaction between NCS-1 and the C-terminal cytoplasmic tail of the Cav2.1 α-subunit. Using distinct but complementary approaches, including in vitro binding of bacterially expressed recombinant proteins, fluorescence spectrophotometry, isothermal titration calorimetry, nuclear magnetic resonance, and expression of fluorescently tagged proteins in mammalian cells, we show direct binding and demonstrate that CaM can compete for it. We speculate about how NCS-1/Cav2.1 association might add to the complexity of calcium channel regulation mediated by other known calcium-sensing proteins and how this might help to fine-tune neurotransmission in the mammalian central nervous system.

Item Type:	Article
Additional Information:	Lian, Lu-Yun Pandalaneni, Sravan R Todd, Paul A C Martin, Victoria Marie Burgoyne, Robert D Haynes, Lee P ENG 2014/09/05 06:00 Biochemistry. 2014 30;53(38):6052-62. doi: 10.1021/bi500568v. Epub 2014 Sep 15. ## TULIP Type: Articles/Papers (Journal) ##
Uncontrolled Keywords:	Humans, Calcium, Neuropeptides, Calcium Channels, N-Type, Cloning, Molecular, Protein Binding, Neuronal Calcium-Sensor Proteins
Depositing User:	Symplectic Admin
Date Deposited:	09 Mar 2015 09:18
Last Modified:	05 Oct 2023 09:26
DOI:	10.1021/bi500568v
Related URLs:	Author Publisher
URI:	https://livrepository.liverpool.ac.uk/id/eprint/2007921

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