Molecular characterization of alpha subunit 1 of sodium pump (ATP1A1) gene in Camelus dromedarius: its differential tissue expression potentially interprets the role in osmoregulation

Abstract

Background: Dromedary or one-humped camel (Camelus dromedarius) is distinctively acclimatized to survive the arid conditions of the desert environment. It has an excellent ability to compete dehydration with substantial tolerance for rapid dehydration. Therefore, it offers an excellent model for studying osmoregulation. Molecular characterization of Na⁺/K⁺ ATPase as a central regulator of electrolyte normohemostasis affords a better understanding of this mechanism in camel. Here is the first to resolve the full-length of alpha-1 subunit of sodium pump (ATP1A1) gene with its differential expression in dromedary tissues.

Results: The nucleotide sequence for the recovered full cDNA of ATP1A1was submitted to the GenBank (NCBI GenBank accession #MW628635) and bioinformatically analyzed. The cDNA sequence was of 3760 bp length with an open reading frame (ORF) of 3066 bp encoding a putative 1021 amino acids polypeptide with a molecular mass of 112696 Da. Blast search analysis revealed the shared high similarity of dromedary ATP1A1gene with other known ATP1A1genes in different species. The comparative analysis of its protein sequence confirmed the high identity with other mammalian ATP1A1 proteins. Further transcriptomic investigation for different organs was performed by real-time PCR to compare its level of expression among different organs. The results confirm a direct function between the ATP1A1 gene expression and the order of vital performance of these organs. The expression of ATP1A1 mRNA in the adrenal gland and brain was significantly higher than that in the other organs. The noticed down expression in camel kidney concomitant with overexpression in the adrenal cortex might interpret how dromedary expels access sodium without water loss with relative high ability to restrain mineralocorticoid-induced sodium retention on drinking salty water.

Conclusion: The results reflect the importance of sodium pump in these organs. Na⁺/K⁺ ATPase in the adrenal gland and brain than other organs.

Keywords: ATP1A1; Bioinformatics; Camelus dromedarius; Molecular characterization.