Identification of a human brain-specific gene, calneuron 1, a new member of the calmodulin superfamily

The calmodulin superfamily includes the calmodulins, calcium-binding protei ns, and related genes. Herein, we describe the cloning and characterization of human calneuron 1 (CALN1). CALN1 encodes a novel neuron-specific protei n that maps to chromosome 7q11, CALN1 spans a large genomic region (>360 kb ). Sequence comparison shows significant similarity with the calmodulin sup erfamily of genes, especially in the two conserved EF-hand motifs. The mous e orthologous gene (Caln1) shows little prenatal expression, with highest e xpression at Postnatal Day 21, In situ hybridization to adult mouse brain s hows high expression in the cerebellum, hippocampus, and cortex. The high e xpression of this gene exclusively in brain, the developmental changes in e xpression levels, the high homology with calmodulin which indicates a poten tial role in signal transduction, and the cellular localization of the mRNA suggest that CALN1 has a significant role in the physiology of neurons and is potentially important in memory and learning. (C) 2001 Academic Press.