Reactome | Calcium Influx through Voltage-gated Calcium Channels

Calcium Influx through Voltage-gated Calcium Channels

Stable Identifier

R-HSA-265645

Type

Reaction [transition]

Species

Homo sapiens

Compartment

plasma membrane

ReviewStatus

5/5

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Calcium Influx through Voltage-gated Calcium Channels

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Voltage-gated calcium channels respond to a change in voltage across the plasma membrane by opening and allowing free movement of calcium ions. In an unstimulated cell the concentration of calcium ions outside the cells is higher than inside due to calcium transporters so channel opening results in an influx of calcium into the cytosol. In the cytosol the calcium ions cause an immediate exocytosis of the readily releasable pool of docked insulin granules as well as a migration of reserve granules toward the plasma membrane where they will be released during the second, sustained phase of insulin secretion.
Mouse and human beta cells are known to contain L type channels Cav1.2 and Cav1.3, both of which have been shown to physically associate with docked insulin granules via Syntaxin1A. Cav1.2 and Cav1.3 predominate in the initial rapid release of insulin. Human beta cells also contain the P/Q type channel Cav2.1 and the R type channel Cav2.3. Cav2.3 is involved in regulating the second, sustained phase of insulin release but signaling and regulatory differences between the two phases of secretion are not fully characterized. Human cells also exhibit T-type (brief burst) calcium currents but the responsible channel has not been identified.

Literature References

PubMed ID	Title	Journal	Year
17660294	The role of distal S6 hydrophobic residues in the voltage-dependent gating of CaV2.3 channels Dionne, F, Raybaud, A, Baspinar, EE, Sauvé, R, Dodier, Y, Parent, L	J Biol Chem	2007
15504896	Modal gating of human CaV2.1 (P/Q-type) calcium channels: I. The slow and the fast gating modes and their modulation by beta subunits Brust, PF, Fellin, T, Harpold, MM, Luvisetto, S, Williams, ME, Hivert, B, Pietrobon, D, Spagnolo, M, Stauderman, KA	J Gen Physiol	2004
11815462	A subset of 50 secretory granules in close contact with L-type Ca2+ channels accounts for first-phase insulin secretion in mouse beta-cells Renström, E, Eliasson, L, Rorsman, P, Barg, S	Diabetes	2002
16513675	Characterization of voltage-dependent sodium and calcium channels in mouse pancreatic A- and B-cells Welling, A, Hofmann, F, Vignali, S, Leiss, V, Karl, R	J Physiol	2006
15000528	Voltage-operated calcium channel heterogeneity in pancreatic beta cells: physiopathological implications Carrera, P, Passafaro, M, Craig, P, Giorgi-Rossi, P, Volsen, S, Sher, E, Davalli, A, Codignola, A, Giovannini, F	J Bioenerg Biomembr	2003
1309948	Cloning of the alpha 1 subunit of a voltage-dependent calcium channel expressed in pancreatic beta cells Blondel, O, Seino, M, Takeda, J, Bell, GI, Johnson, JH, Seino, S, Chen, L	Proc Natl Acad Sci U S A	1992
11815460	Signals and pools underlying biphasic insulin secretion Nenquin, M, Ravier, MA, Ishiyama, N, Jonas, JC, Henquin, JC	Diabetes	2002
10424882	Immunohistochemical detection of alpha1E voltage-gated Ca(2+) channel isoforms in cerebellum, INS-1 cells, and neuroendocrine cells of the digestive system Hescheler, J, Vajna, R, Pereverzev, A, Schneider, T, Volsen, SG, Grabsch, H, Klöckner, U, Weiergräber, M, Schramm, M, Beattie, RE, Henry, M	J Histochem Cytochem	1999
15585596	Beta-cell CaV channel regulation in physiology and pathophysiology Berggren, PO, Yang, SN	Am J Physiol Endocrinol Metab	2005
16868246	The role of voltage-gated calcium channels in pancreatic beta-cell physiology and pathophysiology Berggren, PO, Yang, SN	Endocr Rev	2006
11815463	Triggering and augmentation mechanisms, granule pools, and biphasic insulin secretion Straub, SG, Yajima, H, Gunawardana, S, Sharp, GW, Daniel, S, Bratanova-Tochkova, TK, Mulvaney-Musa, J, Cheng, H, Schermerhorn, T, Liu, YJ	Diabetes	2002