Characterization of a voltage-activated K-channel gene cluster on human chromosome 12p13.

The Shaker related alpha-subunit subfamily of human voltage-activated KCNA-channels is encoded by several genes in the human genome. We have isolated yeast artificial chromosomes (YACs) spanning approximately 1 Mb of human chromosome 12p13 DNA. Molecular biological characterization of the YAC-insert DNAs revealed that three KCNA genes--KCNA1, KCNA5, KCNA6--are clustered within approximately 300 kb of insert-DNA derived from chromosome 12p13. The KCNA gene cluster has been conserved between mouse and human. The three KCNA genes in the cluster are transcribed from the same DNA strand being arranged in a head-to-tail fashion in the order KCNA6-KCNA1-KCNA5. Northern blot analyses of the KCNA1, KCNA5 and KCNA6 mRNAs in different human brain areas show that the genes are distinctly expressed. Therefore, they may be transcribed independently of each other.