Tracing the evolutionary history of novel hormone asprosin: An in silico study across vertebrates

Although, asprosin is implicated in regulation of various physiological functions and metabolic disorders, there are no reports in non-mammalian vertebrates except in fish Channa punctata. Hence, in this study we explore the asprosin across the vertebrate group through in silico analysis. This novel hormone is by product of enzymatic cleavage of profibrillin protein (encoded by FBN1 gene) by furin protease. We have focused on the comparative analysis of physicochemical properties, structure and evolutionary relationship of putative asprosin. The physicochemical properties of putative asprosin across the vertebrate groups revealed thermostability, ex vivo stability and its hydrophilic nature. The secondary and tertiary structures of putative asprosin revealed beta strands that provide the stability and help in folding of protein. The sequence homology of putative asprosin primary sequence reveals more than 50% conservation across the vertebrates. The crucial post-translational modifications such as phosphorylation and glycosylation are present in putative asprosin. Asprosin was observed to be subjected to purifying selection, suggesting limited changes in structure and function of asprosin over extensive evolutionary period. Further, phylogenetic analysis of asprosin showed that bony fishes form a separate clade distinct from mammals, birds, reptiles and amphibians. This study for the first time provides an insight into the conservation of fbn1 encoded profibrillin protein, furin cleavage site in profibrillin protein and its C-terminal cleavage product, asprosin, across the vertebrate groups. The conserved physicochemical properties and strong purifying selection showed that asprosin was under strong evolutionary pressure.