High consumption of ethanolic beverages facilitates neurodegeneration,but the mechanism of this process still remained elusive.Suppression subtractive hybridization (SSH) is a technique for detection of rare transcripts.With SSH approach,we identified one ethanol response gene Cab45,which was down-regulated by ethanol with time-dependent manner in B104 cells.The full-length sequence of Cab45 gene was obtained by 5-RACE (5Rapid Amplification of cDNA Ends) for the first time in rat.Based on the sequence of deduced amino acid of rat Cab45,the alignment was conducted with its counterparts in different species and displayed a high conservation.Using different tissues in rat and cell lines,Cab45 was characterized by a ubiquitous expression and differentiation dependent down-regulation.Given that ethanol facilitates some cell differentiation,we hypothesize that Cab45 is involved in ethanol-mediated differentiation.With transient transfection,the function of Cab45 was investigated by up-regulation and down-regulation in PC12 cells.Ethanol treatment and UV exposure were conducted subsequently and cell proliferations were detected by MTT (Methyl Thiazolyl Tetrazolium) approach.It revealed that the up-regulation of Cab45 modulated the impairment elicited by ethanol and UV in transfected cells.As a member of new calcium binding protein family,the exact role of Cab45 still remains unclear.