miRNA proxy approach reveals hidden functions of glycosylation

Abstract

SignificanceCarbohydrates hold an unprecedented capacity for altering biological function, but determining which glycans and underlying enzymes are crucial for a specific biological pathway is a major impediment to our understanding of this posttranslational modification. Here we demonstrate that the mRNA target networks of microRNA (miRNA), small noncoding RNA, identify glycosylation enzymes acting as regulatory elements within a biological pathway. Leveraging the miRNA-200 family (miR-200f), regulators of epithelial-to-mesenchymal transition (EMT), we identify multiple promesenchymal glycosylation enzymes. Silencing miR-200f–targeted glycogenes phenocopies the effect of miR-200f, inducing mesenchymal-to-epithelial transition. These enzymes are upregulated in TGF-β–induced EMT, suggesting tight integration within the signaling network. Our work indicates that miRNA networks can be used to identify crucial glycosylation enzymes driving disease states.

MicroRNA-424 Predicts a Role for β-1,4 Branched Glycosylation in Cell Cycle Progression

“…Glycosylation can play a role in mediating such signals through altering the trafficking and sensitivity of cell surface cytokine and growth factor receptors (18,(37)(38)(39). MicroRNA, which shapes the identity of a cell through fine-tuned regulation of gene expression, allows us to predict the biological role of specific glycosylation enzymes and the glycans they synthesize (miRNA proxy approach) (8,9). Herein we demonstrate that miR-424, a cell cycle regulator, targets the 3Ј-UTR of the glycosylation-related genes MGAT4A, OGT, and GALNT13, suggesting these enzymes may play a role in cell cycle regulation.…”

“…Much like miRNA, glycosylation has the ability to exert global regulatory effects within the cell and its surroundings, and dysregulation can lead to biological disorders (7). Recent work by our laboratory has shown that miRNAs are important regulators of glycosylation (8) and can be used as a proxy to define the biological functions of glycosylation enzymes (9).…”

Multi-level regulation of cellular glycosylation: from genes to transcript to enzyme to structure

“…Multiple laboratories have demonstrated that downregulation of single glycogene (or other gene) targets of miRNA mimic the biological effects of the miRNA [31–33]. Thus, miRNAs could be used as a proxy to identify glycosylation enzymes involved in the pathways they regulate (miRNA proxy approach) [32,33]. The miRNA proxy approach has been applied to identify functionally relevant glycogenes impacting cell states like epithelial-to-mesenchymal transition (EMT) [32] and the cell cycle [33].…”

“…Thus, miRNAs could be used as a proxy to identify glycosylation enzymes involved in the pathways they regulate (miRNA proxy approach) [32,33]. The miRNA proxy approach has been applied to identify functionally relevant glycogenes impacting cell states like epithelial-to-mesenchymal transition (EMT) [32] and the cell cycle [33]. For example, miR-200b, a regulator of EMT, was found to regulate a set of glycogenes from hard to analyze cohorts those involved in glycolipid (ST3GAL5 and ST6GALNAC5) and non-canonical O-glycan biosynthesis (B3GLCT).…”

“…For example, miR-200b, a regulator of EMT, was found to regulate a set of glycogenes from hard to analyze cohorts those involved in glycolipid (ST3GAL5 and ST6GALNAC5) and non-canonical O-glycan biosynthesis (B3GLCT). Downregulation of these glycogenes using shRNA phenocopied the miRNA, showing a role for these genes in the control of EMT [32]. This work opens up the possibility of leveraging post-transcriptional regulation of glycosylation as a means to reveal critical functional changes in the glycome that underlie biological processes.…”