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