Structure and distribution of a broadly expressed atypical sodium channel

A cDNA clone isolated from a rat dorsal root ganglion library encodes a 195 kDa voltage-gated sodium channel-like protein (SCL-11) with homology to the mouse (87%) and human (72%) atypical Na+ channels and rat partial clone NaG (98%). Two dominant mRNAs of 4.5 and 7 kb are expressed. The transcripts are present in lung, Schwann cells, pituitary and tissues containing smooth muscle cells. No functional channels could be detected on oocyte injection with cRNA, consistent with the absence of structural features necessary for voltage-gated sodium channel activity.