Genome-wide identification, characterization and function analysis of PRMT family in relation to fruit ripening in banana

Abstract

Protein arginine methylation is an important post-translational modification involved in different cellular processes, such as transcriptional regulation, RNA processing, DNA repair and signaling. Protein arginine methylation is catalyzed by protein arginine methyltransferases (PRMTs). However, little information on the involvement of PRMT-mediated protein arginine methylation in fruit ripening is available. Here, we identified and cloned nine PRMTs from the banana genome and characterized their phylogenetic relationship, conserved domains, gene structure and promoter cis-element. In addition, subcellular localization of MaPRMT proteins, expression profiles of MaPRMTs and protein arginine methylation levels during banana fruit ripening also were investigated. All the nine MaPRMTs were localized to cytoplasm and nucleus, suggesting that they might be involved in the histone and non-histone arginine methylation modification. The transcriptional levels of MaPRMT4B, MaPRMT6A and MaPRMT6B were significantly upregulated as fruit ripening proceeded. The upregulation was promoted by ethylene treatment, but postponed by 1-MCP treatment. Furthermore, the levels of protein arginine methylation, including asymmetric (aDMA) and symmetric (sDMA) dimethylarginine, were upregulated in banana during fruit ripening. These results suggested that PRMTs-mediated protein arginine methylation were implicated in banana fruit ripening.