Re: Randen's comment on defining channels

7 June 2004

Randen L. Patterson

A small rebuttle 1)"There is simply no way that "fluorescent calcium entry" recordings can provide such a fingerprint"

Wouldn't siRNA deletion of a calcium channel, and looking at a change in bulk calcium flow using fura provide a molecular fingerprint?

2)"I agree, but you are talking about the behavior and role of the channel in signaling. Whilst I would be the first to agree that these are essential components of our understanding of the channel, I do not agree that they offer much to help in its identification. "

So should we as a field abandon the ideas of proteomic approaches to link proteins which we know can influence calcium entry to the channels themselves?

3)"Personally, I find the Ba2+/Sr2+ story for most entry pathways very confusing and not very informative."

I agree entirely on this point. There are papers that exist in the literature that talk about TRPC channels being calcium channels, yet in not one place in the entire manuscript do they look at calcium flux through these TRPC channels. In fact, has anyone demonstrated that an overexpressed TRPC channel carries calcium at all? How can they be sure that the currents they are observing are not from a heteromultimer with endogenous machinery? (back to Trevor's original arguement)