Abstract
Selenium is an essential micronutrient involved in the modulation of oxidative stress, redox signalling, immunity and protein folding (2). Sec binds to the active site of proteins forming selenocysteines, and therefore a selenoprotein (3, 5). In the translational process, Sec is inserted to the selenoprotein encoded by a UGA stop codon. The presence of an RNA stem-loop structure located in the 3’ UTR, the Selenocysteine Insertion Sequence (SECIS), allows the insertion of a Sec instead of what would normally be a stop signal (5,6). The development of tools based on the recognition of SECIS elements permitted the identification of the selenoproteomes in the different species (11). On the other hand, the conservation of the different selenoproteins throughout evolution also allowed the discovering of the different selenoproteomes. Closely related species show in general similarity between their selenoproteomes (10). It is for this reason that the rodent species Ictidomys tridecemlineatus, whose selenoproteome is registered in SelenoDB databases, has been used as reference in this study to determine the selenoproteome of another rodent, Spermophilus dauricus. The aim of the study was to associate by homology the sequences of Ictidomys tridecemlineatus selenoproteins with sequences of the genome of Spermophilus dauricus in order to determine the selenoproteins on this specie. We also used Homo sapiens selenoproteome as reference for the analysis. The results have been obtained by using an automatized programme designed for us and then confirmed by two other computational methods: SECISearch3 and Seblastian, which predict selenoprotein sequences encoded upstream of SECIS elements (11).