Molecular cloning and characterization of hNP22: a gene up-regulated in human alcoholic brain

An improved differential display technique was used to search for changes i n gene expression in the superior frontal cortex of alcoholics, A cDNA frag ment was retrieved and cloned. Further sequence of the cDNA was determined from 5' RACE and screening of a human brain cDNA library. The gene was name d hNP22 (human neuronal protein 22). The deduced protein sequence of hNP22 has an estimated molecular mass of 22.4 kDa with a putative calcium-binding site, and phosphorylation sites for casein kinase II and protein kinase C. The deduced amino acid sequence of hNP22 shares homology (from 67% to 42%) with four other proteins, SM22 alpha, calponin, myophilin and mp20. Sequen ce homology suggests a potential interaction of hNP22 with cytoskeletal ele ments. hNP22 mRNA was expressed in various brain regions but in alcoholics, greater mRNA expression occurred in the superior frontal cortex, but not i n the primary motor cortex or cerebellum. The results suggest that hNP22 ma y have a role in alcohol-related adaptations and may mediate regulatory sig nal transduction pathways in neurones.