Session 1: Physiological Processes that Mediate Activation of Calcium Entry Channels

24 May 2004

E-Conference Chairpersons

This session is focused on the main question of what the physiological transduction processes that mediate activation of calcium entry channels are.

Specific issues include

(a) The role of calcium stores in activating entry:

Are changes in intracellular stores necessary or sufficient input, or both, to activate calcium entry? Are intracellular calcium stores physiologically depleted under normal cellular conditions?

(b) Distinctions between receptor-operated and store-operated calcium entry:

Do receptors activate distinct calcium entry events from those stimulated by store-emptying? Are the calcium entry events activated by receptors and emptied stores independent or integrated?

(c) The role of intracellular calcium release channels:

Do InsP3 receptors or ryanodine receptors, or both, mediate or modify calcium entry events?

(d) The function of mediators and adaptors in calcium entry:

What role is played by structural or adaptor proteins (including Homer, NHERF, InsP3Rs, and PLC-gamma), or by soluble cellular messengers (such as InsP3, cyclic nucleotides) and lipid messengers (including diacylglycerol, arachidonic acid, and PIP2)?