Ashoka University is a private university located in Sonipat, Haryana, India, focusing on liberal arts and sciences. It was established in 2014.&nbsp;It is guided by an academic council of academics and scholars from around the world. The council sets the university&#39;s academic standard, advising on matters of curriculum, faculty hiring and research.&nbsp;

Ashoka University offers a full-time 3 (+ 1) year undergraduate programme. The University comprises of&nbsp;2500 plus students, with a mix of both national and international students.&nbsp; &nbsp;

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Ashoka University

Mutations in the sialic acid biosynthesis enzyme GNE lead to a late-onset, debilitating neuromuscular disorder, GNE myopathy, characterized by progressive skeletal muscle weakness. The mechanisms responsible for skeletal muscle specificity, late-onset, and disease progression are unknown. Our main aim is to understand the reason for skeletal muscle-specific phenotype. To answer this question, we have analyzed the expression profile of the GNE gene and its multiple mRNA variants in different human tissues. A combinatorial approach encompassing bioinformatics tools and molecular biology techniques was used. NCBI, Ensembl, and GTEx were used for data mining. The expression analysis of GNE and its variants was performed with cDNA tissue panel using PCR and targeted RNA-seq. Among nine different GNE isoforms reported in this study, transcript variants 1, X1, and X2 were not tissue specific. Transcript variants 1, 6, X1, and X2, were found in skeletal muscles suggesting their possible role in GNE myopathy. In the current study, we present new data about GNE expression patterns in human tissues. Our results suggest that there may be a link between tissue-specific pathology and isoform pattern in skeletal muscles, which could provide clues for the development of new treatment strategies for GNE myopathy

Department of Biology

World University root node

Journal of Muscle Research and Cell Motility

Tissue-specific isoform expression of GNE gene in human tissues

UDP-GlcNAc 2-epimerase/ManNAc kinase (GNE) is a bifunctional enzyme (N-terminal epimerase and C-terminal Kinase domain) that catalyses the rate limiting step in <a href="https://www.sciencedirect.com/topics/biochemistry-genetics-and-molecular-biology/sialic-acid">sialic acid</a> <a href="https://www.sciencedirect.com/topics/biochemistry-genetics-and-molecular-biology/anabolism">biosynthesis</a>. More than 200 homozygous missense or compound heterozygous mutations in GNE have been reported worldwide to cause a rare neuromuscular disorder, GNE myopathy. It is characterized by a slowly progressive defect in proximal and distal skeletal muscles with patients becoming wheel-chair-bound. There are no current approved therapies available for GNE myopathy. ManNAc therapy is currently in advanced clinical trials and has shown signs of slowing the disease progression in a phase 2 trial. The present study aims to understand the effect of GNE mutation on its <a href="https://www.sciencedirect.com/topics/biochemistry-genetics-and-molecular-biology/enzyme-activity">enzymatic activity</a> and identification of potential small effector molecules. We characterized different GNE mutations (p.Asp207Val, p.Val603Leu, p.Val727Met, p.Ile618Thr and p.Arg193Cys) prevalent in Asian population that were cloned, expressed and purified from Escherichia coli as full-length <a href="https://www.sciencedirect.com/topics/biochemistry-genetics-and-molecular-biology/recombinant-proteins">recombinant proteins</a>. Our study demonstrates that full length GNE can be expressed in E.&nbsp;coli in its active form and analysed for the functional activity. Each mutation showed variation in epimerase and kinase activity and responded to the small effector molecules (metformin, BGP-15 <a href="https://www.sciencedirect.com/topics/biochemistry-genetics-and-molecular-biology/kaempferol">kaempferol</a>, <a href="https://www.sciencedirect.com/topics/biochemistry-genetics-and-molecular-biology/catechin">catechin</a>, quercetin) in a differential manner. Our study opens an area for futuristic structural determination of full length GNE and identification of potential therapeutic molecules.

Biochimie

Functional characterization of GNE mutations prevalent in Asian subjects with GNE myopathy, an ultra-rare neuromuscular disorder