Re: Randen's comment on defining channels

8 June 2004

Trevor Shuttleworth

Re: Tthe channel fingerprint -- I think maybe we are talking about two different things. The experiment you describe would certainly help identify the contribution of a particular channel in cellular responses (its "functional" fingerprint if you like).

However, specific siRNA techniques (as opposed to systematic siRNA screening) require knowledge of the molecular identity of the channels involved. In the case of at least two widely-expressed, highly Ca2+-selective channels involved in Ca2+ entry (CRAC and ARC channels), this is not known.

I think of our current situation much like a criminal investigation. If you already have a clearly identified suspect in custody, then an appropriate DNA test may put the suspect at the scene of the crime and clinch the case (the siRNA experiment).

But, if you have no real idea who the perpetrator is, you have to start by building a file of critical bits of information based on the evidence available that may help narrow down the field and direct your search in an appropriate direction -- if entry to the scene of the crime was achieved via a 12 inch hole-- it is no good looking at any NFL linemen as potential suspects!