Signalling nucleotides are key molecules that help bacteria to rapidly coordinate cellular pathways and adapt
to changes in their environment. During the past ten years, the nucleotide-signalling field has seen much
excitement, as several new signalling nucleotides have been discovered in both eukaryotic and bacterial cells.
The fields have since advanced quickly, aided by the development of important tools such as the synthesis of
modified nucleotides, which combined with sensitive mass spectrometry methods, allowed for the rapid
identification of specific receptor proteins along with other novel genome-wide screening methods. In this
review, we will describe the principle concepts of nucleotide signalling networks and summarize the recent
work that led to the discovery of the novel signalling nucleotides. We will also highlight current approaches
applied to the research in the field as well as resources and methodological advances aiding in a rapid
identification of nucleotide specific receptor proteins.