Identification and characterization of TMEM16H gene in silico

TMEM16A gene is located within the CCND1-ORAOV1-FGF19-FGF4-FGF3-TMEM16A-FADD-PPFIA1-CTTN (cortactin or EMS1) amplicon at human chromosome 11q13.3. TMEM16A, TMEM16B, TMEM16C, TMEM16D, TMEM16E (GDD1), TMEM16F, TMEM16G and TP53I5 are TMEM16 family proteins with TM16H1, TM16H2 and TM16H3 domains. Here, we identified and characterized TMEM16H gene by using bioinformatics. Human TMEM16H gene, consisting of 18 exons, was located at human chromosome 19p13.11. AB046843.2 cDNA corresponded to TMEM16H isoform 1 without intron 17, while CR616031.1 cDNA corresponded to TMEM16H isoform 2 with retained intron 17. TMEM16H isoforms were eight-transmembrane proteins with TM16H3 domain. The last exon of isoforms 1 and 2 corresponded to C-terminal 122 and 227 aa, respectively. Human TMEM16H isoform 1 was the major transcript, while isoform 2 was the minor transcript prone to non-sense mediated mRNA decay (NMD). TMEM16H mRNA was expressed in embryonic stem (ES) cells, fetal brain, and neural tissues. Mouse Tmem16h representative cDNA was determined by assembling BC027735.1 and BC059855.1 cDNAs. Mouse and rat Tmem16h genes encoded Tmem16h proteins similar to human TMEM16H isoform 2. The regions corresponding to exons 17 and 18 of human TMEM16H gene were not separated by intron within mouse and rat Tmem16h genes. Insertion of intron 17 into human TMEM16H gene during evolution resulted in the generation of TMEM16H isoform 1. This is the first report on identification and characterization of the TMEM16H gene as well as on the molecular evolution of TMEM16H.