2’-5’-oligoadenylate synthetase1 (OAS1): Molecular, structural, integrative Bioinformatics and functional analysis in the endometrium of goat ( Capra hircus )

An interferon-inducible gene, 2’-5’-oligoadenylate synthetase-1 (OAS1), plays an essential role in uterine receptivity and conceptus development by controlling cell growth and differentiation in addition to its anti-viral activities. However, the specific part of OAS1 is not yet documented in the goat. Therefore, in the present study, the coding sequence (CDS) of the OAS1 gene was amplified, sequenced and characterized through various Bioinformatics tools. Its temporal expression profile was also examined in the endometrium of caprine (cp) for the first time. A fragment of the cpOAS1 gene, 890 bp in length, was amplified from complementary DNA (cDNA). Nucleotide and deduced amino acid sequences revealed 99.6 to 80.4 % and 99.3 to 72.3 % identities with that of ruminants and non-ruminants, respectively. A constructed phylogenetic tree revealed that sheep and goats belong to the same clade but differ from large ruminants. Besides the Physico-chemical characteristics, its localization, various posttranslational modifications, immunogenic sites, possible domains, various motifs, and interactions with other probable proteins were predicted. In addition to the secondary structure, the three-dimensional structure was predicted using homology modelling servers and a refined model, generated by the Swiss model was the best one as based on stereochemistry validated with different programs. Further, relative expression of cpOAS1 mRNA and protein was determined by quantitative real-time PCR (qPCR) and western blot, respectively, in the endometrium of pregnant and cyclic does. Caprine OAS1 protein (42/46kDa) was detected in the endometrium of pregnant and cyclic does. Both cpOAS1 mRNA and protein were expressed maximally (P<0.05) in the endometrium during pregnancy as compared to cyclic does. It is concluded that the cpOAS1 sequence is conserved and integrative Bioinformatics analysis provides a sound foundation for further structural and functional characterization of cpOAS1 protein in the establishment of pregnancy in goats.