Genome-wide identification, characterization and expression profiles of heavy metal ATPase (HMA۳) in plants

HMA (heavy metal associated) is a member of the ATPases protein family involved in metal transport in plants. This study characterizes several HMA۳ homologs and infers their molecular functions in different plant species. Arabidopsis AtHMA۳ (AT۴G۳۰۱۲۰) was used as a reference to retrieve ۱۱ HMA۳ homologs having ۹۷-۱۰۰% query cover, ۵۳۵-۵۴۲ residues, ۵۶۹۸۳ to ۵۸۶۴۲ (Da) molecular weight, and ۵.۷۴ to ۸.۱۶ pI value, ۲۹.۱۰ to ۳۳.۸۹ instability index, and ۰.۲۲۲ to ۰.۳۸۰ grand average of hydropathicity. Topological analyses showed ۴ transmembrane domains in these HMA۳ homologs positioned similarly in terms of cytoplasmic and non-cytoplasmic regions along with ~۲۲-۲۸% 𝛼-helices, ~۲۲-۲۸% extended strands, and ~۵۰% random coils. HMA۳ protein of Arabidopsis lyrata subsp. lyrata and Eutrema salsugineum are located at chromosome ۲, while others are positioned at chromosome ۴. All these HMA۳ homologs are localized in the plasma membrane sharing a few common biological and molecular functions. Besides, these HMA۳ genes contain ۸-۹ exons in which promoter positions are varied among the homologs. The cis-acting elements of HMA۳ genes were projected to be involved with stress response, anaerobic induction, and light responsive regulation in plants. Three out of five motifs encode E۱-E۲_ATPase involved in proton-pumping in the plasma membrane. The Arabidopsis thaliana HMA۳ protein clustered with Camelina sativa and Capsella rubella show a close phylogenetic relationship. Also, AtHMA۳ exhibits a close association with AtHMA۳ with MTPA۲, ZAT, NRAMP۳, IRT۲, and NRAMP۲ under the local network of AtHMA۳ linked to metal transport. Further, AtHMA۳ is most potentially expressed during senescence, germinating seed, seedlings, young rosette, bolting, and young flower. In addition, AtHMA۳ showed a significant upregulation (>۶.۰ fold) under Fe-deficiency. These findings may provide essential background to perform wet-lab experiments to understand the role of HMA۳ in metal homeostasis.

کلیدواژه ها:

ATPases family ، phylogeny ، conserved motif ، gene interactions ، sequence homology