Cholinergic Receptor, Nicotinic, Alpha 2 (CHRNa2)

Elliott et al. (1996) cloned CHRNA2 from a thalamus cDNA library following low-stringency screening with the rat alpha-4-1 probe. The deduced 503-amino acid protein has a calculated molecular mass of 56.9 kD and contains a signal peptide, 3 N-glycosylation sites, and 4 transmembrane regions. The human and rat proteins share 84% sequence identity.Human evolution is characterized by a dramatic increase in brain size and complexity. To probe its genetic basis, Dorus et al. (2004) examined the evolution of genes involved in diverse aspects of nervous system biology. These genes, including CHRNA2, displayed significantly higher rates of protein evolution in primates than in rodents. This trend was most pronounced for the subset of genes implicated in nervous system development.