The amino sugar, N-acetylglucosamine (GlcNAc), has emerged as an attractive messenger of signaling in the pathogenic yeast Candida albicans, given its multifaceted role in cellular processes, including GlcNAc scavenging, import and metabolism, morphogenesis (yeast to hyphae and white to opaque switch), virulence, GlcNAc induced cell death (GICD), etc. During signaling, the exogenous GlcNAc appears to adopt a simple mechanism of gene regulation by directly activating Ngs1, a novel GlcNAc sensor and transducer, at the chromatin level, to activate transcriptional response through the promoter acetylation. Ngs1 acts as a master regulator in GlcNAc signaling by regulating GlcNAc catabolic gene expression and filamentation. Ndt80-family transcriptional factor Rep1 appears to be involved in the recruitment of Ngs1 to GlcNAc catabolic gene promoters. For promoting filamentation, GlcNAc adopts a little modified strategy by utilizing a recently evolved transcriptional loop. Here, Biofilm regulator Brg1 takes up the key role, getting up-regulated by Ngs1, and simultaneously induces Hyphal Specific Genes (HSGs) expression by down-regulating NRG1 expression. GlcNAc kinase Hxk1 appears to play a prominent role in signaling. Recent developments in GlcNAc signaling have made C. albicans a model system to understand its role in other eukaryotes as well. The knowledge thus gained would assist in designing therapeutic interventions for the control of candidiasis and other fungal diseases.

Gatekeepers that control the import of molecules to be fed to the metabolic pathways are mainly nutrient transporters that are housed in the plasma membrane. Changes in metabolism and environment are mostly accomplished by regulating the surface expression of transporters (Haguenauer-Tsapis & Andre, 2004;Becuwe and Léon, 2014). Since changes in the environment are often abrupt, yeast has developed fast-acting pathways that are not dependent on transcriptional regulation but focus on adaptation by protein trafficking.For example, endocytosis is able to rapidly remove proteins from the cell surface that otherwise might be deleterious under the changed environmental conditions. Therefore, in order to undergo a perfect remodeling in terms of concentration, these surface-proteins often take part in endocytic recycling (Becuwe and Léon, 2014) involving several organellar machineries that include, early endosomes, late endosomes, multivesicular body (MVB), trans-Golgi network (TGN), and lysosomes/vacuole (Katzmann et al., 2002;Haguenauer-Tsapis & Andre, 2004;Sheena and Patricia, 2009). Proteins that enter endocytic vesicles are either destined for degradation in vacuoles or recycled to plasma membrane through a retrograde pathway. The proteins that get degraded are often marked by ubiquitin tags and

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