Discovering the mechanism of capacitative calcium entry

This essay examines the historical significance of an APS classic paper that is freely available online: Kwan CY, Takemura H, Obie JF, Thastrup O, and Putney JW Jr. Effects of MeCh, thapsigargin, and La3+ on plasmalemmal and intracellular Ca2+ transport in lacrimal acinar cells. Am J Physiol Cell Physiol 258: C1006–C1015, 1990. ( http://ajpcell.physiology.org/cgi/reprint/258/6/C1006 )

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PHARMACOLOGY OF CAPACITATIVE CALCIUM ENTRY CHANNELS IN LACRIMAL ACINAR CELLS AND OTHER NON-EXCITABLE CELLS.

Cornea ◽

10.1097/00003226-200011002-00148 ◽

2000 ◽

Vol 19 (Supplement 2) ◽

pp. S115

Author(s):

J W Putney ◽

L M Broad ◽

F-J Braun

Keyword(s):

Acinar Cells ◽

Calcium Entry ◽

Excitable Cells ◽

Capacitative Calcium Entry ◽

Lacrimal Acinar Cells

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Teaching the modes of Ca2+ transport between the plasma membrane and endoplasmic reticulum using a classic paper by Kwan et al.

AJP Advances in Physiology Education ◽

10.1152/advan.00025.2009 ◽

2009 ◽

Vol 33 (3) ◽

pp. 169-174 ◽

Cited By ~ 2

Author(s):

Willmann Liang

Keyword(s):

Endoplasmic Reticulum ◽

Teaching And Learning ◽

Inhibitory Effects ◽

New Graduate ◽

Intracellular Ca ◽

Upper Level ◽

Lacrimal Acinar Cells ◽

Learning Points ◽

Classic Paper

This teaching article uses the report by Kwan et al., “Effects of methacholine, thapsigargin, and La3+ on plasmalemmal and intracellular Ca2+ transport in lacrimal acinar cells,” where the effects of Ca2+-mobilizing agents in regulating Ca2+ fluxes were examined under various conditions. Upper-level undergraduate and new graduate students in physiology are the targe audience. Teaching and learning points are put forth in this article to illustrate 1) the characteristics of methacholine- and thapsigargin-induced Ca2+ responses, 2) the different endoplasmic reticulum Ca2+ stores accessible to methacholine and thapsigargin, 3) the inhibitory effects of La3+ on Ca2+ extrusion and Ca2+ influx, and 4) the facilitatory role of La3+ on endoplasmic reticulum Ca2+ recycling. Each of the above concepts is first explained with references to the figures adapted from the original article. A list of student learning questions then follows, where the answers are found in the teaching notes for the instructors. It is the objective of this article to make both teaching and learning Ca2+ regulation a rewarding experience for all.

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Pacemaker activity in urethral interstitial cells is not dependent on capacitative calcium entry

AJP Cell Physiology ◽

10.1152/ajpcell.00090.2005 ◽

2005 ◽

Vol 289 (3) ◽

pp. C625-C632 ◽

Cited By ~ 21

Author(s):

Eamonn Bradley ◽

Mark A. Hollywood ◽

Noel G. McHale ◽

Keith D. Thornbury ◽

Gerard P. Sergeant

Keyword(s):

Spontaneous Activity ◽

Interstitial Cells ◽

Calcium Entry ◽

Pacemaker Activity ◽

Capacitative Calcium Entry ◽

Intracellular Ca ◽

Inward Currents ◽

Rabbit Urethra ◽

In Cells

The aim of the present study was to investigate the properties and role of capacitative Ca2+ entry (CCE) in interstitial cells (IC) isolated from the rabbit urethra. Ca2+ entry in IC was larger in cells with depleted intracellular Ca2+ stores compared with controls, consistent with influx via a CCE pathway. The nonselective Ca2+ entry blockers Gd3+ (10 μM), La3+ (10 μM), and Ni2+ (100 μM) reduced CCE by 67% ( n = 14), 65% ( n = 11), and 55% ( n = 9), respectively. These agents did not inhibit Ca2+ entry when stores were not depleted. Conversely, CCE in IC was resistant to SKF-96365 (10 μM), wortmannin (10 μM), and nifedipine (1 μM). Spontaneous transient inward currents were recorded from IC voltage-clamped at −60 mV. These events were not significantly affected by Gd3+ (10 μM) or La3+ (10 μM) and were only slightly decreased in amplitude by 100 μM Ni2+. The results from this study demonstrate that freshly dispersed IC from the rabbit urethra possess a CCE pathway. However, influx via this pathway does not appear to contribute to spontaneous activity in these cells.

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Capacitative Calcium Entry

Physiology ◽

10.1152/physiologyonline.1998.13.4.157 ◽

1998 ◽

Vol 13 (4) ◽

pp. 157-163 ◽

Cited By ~ 4

Author(s):

Jaclyn R. Holda ◽

Andrey Klishin ◽

Marina Sedova ◽

Jörg Hüser ◽

Lothar A. Blatter

Keyword(s):

Recent Progress ◽

Calcium Entry ◽

Biophysical Properties ◽

Capacitative Calcium Entry ◽

Entry Pathway ◽

Molecular Identity ◽

Store Depletion ◽

Intracellular Ca

Capacitative Ca2+ entry is a recently discovered Ca2+ entry pathway that is activated on depletion of intracellular Ca2+ stores, providing an avenue for store refilling. Despite recent progress in elucidating the capacitative Ca2+ entry pathway, the mysteries of its molecular identity, its biophysical properties, and the store depletion signal remain.

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