DCAMKL1, a brain-specific transmembrane protein on 13q12.3 that is similar to doublecortin (DCX)

Mutations in the human doublecortin (DCX), a brain-specific putative signaling protein, cause X-linked lissencephaly and subcortical band heterotopia. A predicted 740-amino-acid protein from human brain has two distinct regions, an N-terminal 345-amino-acid region 78% similar to the DCX protein and a C-terminal 427-amino-acid region that contains two transmembrane domains and is 98% homologous to a rat Ca2+/calmodulin-dependent protein kinase. We have designated this protein DCAMKL1. It maps to chromosome 13q12.3-q13, within a 540-kb YAC clone containing markers D13S805 and D13S1164. Northern analysis detected three major transcript isoforms of the DCAMKL1 gene expressed differentially and predominantly in human fetal and adult brain and during mouse embryogenesis (11-17 dpc). These results and its homology with the DCX and Ca2+/calmodulin dependent kinase proteins suggest a likely role for DCAMKL1 transmembrane protein in developing and adult brain, possibly in a pathway of cortical development.