bp(GO:"calcium ion transport")
Calcium signaling pathways are involved both in the toxic action of Abeta and in the protection against that toxicity offered by nicotinic ligands. Given that alpha7 homomeric nAChRs are much more permeable to calcium ions than are most other nAChRs (Bertrand et al., 1993), it is to be expected that nicotinic neuroprotection mediated by nAChRs, notably alpha7, would depend upon the activation of calcium signaling pathways. ABT-418 is a nicotinic agonist that protects primary rat cortical neurons from glutamate toxicity through its activation of alpha7 nAChRs, and this is blocked when calcium is removed from the extracellular medium (Donnelly-Roberts et al., 1996). PubMed:19293145
M1, M3, and M5 all signal primarily via the Galphaq G-protein and induce Ca2+ mobilization and inositol trisphosphate (IP3) production, while M2 and M4 signal via the Galphai G-protein to inhibit cyclic adenosine monophosphate (cAMP) production. PubMed:24511233
M1, M3, and M5 all signal primarily via the Galphaq G-protein and induce Ca2+ mobilization and inositol trisphosphate (IP3) production, while M2 and M4 signal via the Galphai G-protein to inhibit cyclic adenosine monophosphate (cAMP) production. PubMed:24511233
M1, M3, and M5 all signal primarily via the Galphaq G-protein and induce Ca2+ mobilization and inositol trisphosphate (IP3) production, while M2 and M4 signal via the Galphai G-protein to inhibit cyclic adenosine monophosphate (cAMP) production. PubMed:24511233
So far, five mAChR subtypes (M1– M5) have been identified and are divided into two categories based on the manner of signal transduction: M1, M3, and M5 subtypes preferentially interact with the Gq/11 family of G proteins, activating phospholipase C and mobilizing intracellular calcium, while M2 and M4 subtypes couple to the Go/i family, inhibiting adenylate cyclases and reducing intracellular cAMP levels PubMed:24590577
So far, five mAChR subtypes (M1– M5) have been identified and are divided into two categories based on the manner of signal transduction: M1, M3, and M5 subtypes preferentially interact with the Gq/11 family of G proteins, activating phospholipase C and mobilizing intracellular calcium, while M2 and M4 subtypes couple to the Go/i family, inhibiting adenylate cyclases and reducing intracellular cAMP levels PubMed:24590577
So far, five mAChR subtypes (M1– M5) have been identified and are divided into two categories based on the manner of signal transduction: M1, M3, and M5 subtypes preferentially interact with the Gq/11 family of G proteins, activating phospholipase C and mobilizing intracellular calcium, while M2 and M4 subtypes couple to the Go/i family, inhibiting adenylate cyclases and reducing intracellular cAMP levels PubMed:24590577
The subtype alpha4beta2 is characterized by lower calcium ion permeability and a slow desensitization rate compared to the homopentameric alpha7 nAChR (Quick and Lester, 2002) PubMed:25514383
The alpha7 homomeric receptor demonstrates a wide-spread localization in the brain and is characterized by a high calcium ion permeability and a fast desensitization rate (Dani and Bertrand, 2007; Quick and Lester, 2002) PubMed:25514383
The subtype alpha4beta2 is characterized by lower calcium ion permeability and a slow desensitization rate compared to the homopentameric alpha7 nAChR (Quick and Lester, 2002) PubMed:25514383
The five subunits that compose the receptor are assembled around a central hydrophilic pore that mediates the flow of the cations K+, Na+ and Ca++. In the human nervous system, there are eight alpha subunits (alpha2-alpha7, alpha9, alpha10) and three beta subunits (beta2-beta4) that assemble in different combinations to generate a variety of nAChR subtypes with distinct electrophysiological properties and brain localization (Albuquerque et al., 2009; Gotti et al., 2006b, 2007, 2009) PubMed:25514383
Homomeric alpha7 receptors are also abundant and are of particular interest as they show very high calcium permeability and are linked to both physiological and disease processes (Gotti and Clementi, 2004; Hogg et al., 2003; Le Nove` re et al., 2002; Lindstrom, 1997; Picciotto, 2003; Role and Berg, 1996 PubMed:28445721
alpha7 nAChRs also respond to nicotine concentrations roughly an order of magnitude higher than alpha42beta23, and alpha7 nAChRs have high Ca2+ permeability resembling that of NMDA receptors PubMed:21482353
The subtype alpha4beta2 is characterized by lower calcium ion permeability and a slow desensitization rate compared to the homopentameric alpha7 nAChR (Quick and Lester, 2002) PubMed:25514383
The subtype alpha4beta2 is characterized by lower calcium ion permeability and a slow desensitization rate compared to the homopentameric alpha7 nAChR (Quick and Lester, 2002) PubMed:25514383
alpha7 nAChRs also respond to nicotine concentrations roughly an order of magnitude higher than alpha42beta23, and alpha7 nAChRs have high Ca2+ permeability resembling that of NMDA receptors PubMed:21482353
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If you find BEL Commons useful in your work, please consider citing: Hoyt, C. T., Domingo-Fernández, D., & Hofmann-Apitius, M. (2018). BEL Commons: an environment for exploration and analysis of networks encoded in Biological Expression Language. Database, 2018(3), 1–11.