Title : Interactive cloning with the SH3
domain of
N-src identifies a new brain specific ion
channel protein , with homology to
eag and cyclic nucleotide-gated
channels
Abstract :
- We have isolated a novel cDNA, that appears to represent a new class of ion channels , by using the yeast two-hybrid system and the SH3 domain of the neural form of Src ( N-src ) as a bait
- The encoded polypeptide , BCNG-1 , is distantly related to cyclic nucleotide-gated channels and the voltage-gated channels , Eag and H-erg
- BCNG-1 is expressed exclusively in the brain, as a glycosylated protein of approximately 132 kDa
- Immunohistochemical analysis indicates that BCNG-1 is preferentially expressed in specific subsets of neurons in the neocortex, hippocampus, and cerebellum, in particular pyramidal neurons and basket cells
- Within individual neurons, the BCNG-1 protein is localized to either the dendrites or the axon terminals depending on the cell type
- Southern blot analysis shows that several other BCNG-related sequences are present in the mouse genome, indicating the emergence of an entire subfamily of ion channel coding genes
- These findings suggest the existence of a new type of ion channel , which is potentially able to modulate membrane excitability in the brain and could respond to regulation by cyclic nucleotides