It is becoming increasingly clear that cellular signalling and metabolism are not just separate entities but rather are tightly linked. Although nutrient metabolism is known to be regulated by signal transduction, an emerging paradigm is that signalling and transcriptional networks can be modulated by nutrient-sensitive protein modifications, such as acetylation and glycosylation, which depend on the availability of acetyl-CoA and sugar donors such as UDP-N-acetylglucosamine (UDP-GlcNAc), respectively. The integration of metabolic and signalling cues allows cells to modulate activities such as metabolism, cell survival and proliferation according to their intracellular metabolic resources.