-GlcNAcylation confers protection against infection in through ubiquitination.

Glycosylation is one of the most prevalent post-translational modifications in biological systems. In , -GlcNAcylation has been shown to be actively involved in the regulation of dauer formation and detoxification of toxins secreted by invading pathogens. On this backdrop, the present study is focused on understanding the role of -GlcNAcylation in during infection using a gel based proteomic approach. Results of time course killing assays with wild-type and mutants of glycosylation and comparison of results revealed an increase in the survival of the mutant when compared to wild-type N2 and the mutant. Increased survival of N2 upon infection in the presence of -(2-acetamido-2-deoxy-d-glucopyranosylidenamino) -phenylcarbamate (PUGNAc-an OGA inhibitor) further confirmed the involvement of -GlcNAcylation in protecting from infection. The two-dimensional gel-based proteomic analysis of the control and infected mutant followed by mass spectrometric identification of differentially expressed proteins has been carried out. The results revealed that key proteins involved in ubiquitination such as Cullin-1 (CUL-1), Cullin-3 (CUL-3), BTB and MATH domain-containing protein 15 (BATH-15), ubiquitin-conjugating enzyme E2 variant 3 (UEV-3) and probable ubiquitin-conjugating enzyme E2 7 (UBC-7) are upregulated. Real-time PCR analysis further confirms the upregulation of genes encoding the above-mentioned proteins which are involved in the ubiquitin-mediated pathways in . In addition, treatment of wild-type N2 and the mutant with PUGNAc + suramin and suramin (an ubiquitination inhibitor), respectively has resulted in increased sensitivity to infection. Hence, it is presumed that upregulation of proteins involved in the ubiquitination pathway could be the key regulatory mechanism responsible for the enhanced survival of the mutant during infection.