Alternative splicing, expression and cellular localization of Calneuron-1 in the rat and human brain.

Calneuron-1 and -2 are members of the neuronal calcium-binding protein family (nCaBP). They are transmembrane Calmodulin-like EF-hand Ca(2+)-sensors, and a function in the control of Golgi-to-plasma membrane vesicle trafficking has been assigned to both proteins. In this paper, we describe the distribution of Calneuron-1 in rat and human brains. We show that Calneuron-1 is ubiquitously expressed in all brain regions examined. The protein is most abundant in Purkinje cells of the cerebellum and principal neurons of the cortex and limbic brain whereas no expression in glial cells is apparent. In addition, we identify two novel splice isoforms of Calneuron-1 with extended N-termini. These isoforms are particular abundant in the cerebellum. Taken together, these data set grounds for a better understanding of the cellular function of Calneurons.