Molecular Physiology of Sodium-Calcium Exchange

(0609) The retinal rod Na-Ca,K exchanger

The finding, that your truncated bovine NCKX1/Bvdel is clearly K-dependent is remarkable. The problem of expressing the bovine NCKX in HEK293 cells is obviously very hard. I understand from your paper, that you find very little if any functional exchanger after expression the full length clone in HEK293 cells. Navangione et al. (Biophys. J. 73, 45, (1997)) observed that Na-Ca exchange of the NCKX after expression in HEK293 cells was not K-dependent. These authors considered the possibility of an additional regulatory protein which confers K-dependency to the exchanger. Do you suggest that the full length bovine NCKX1 is only partially functioning after expression in HEK 293 cells due to imperfect expression’?

Tue Dec 8