UniProt release 12.1

Over 18,500 phosphorylation sites identified by mass spectrometry in UniProtKB/Swiss-Prot

Phosphorylation is a key reversible modification that regulates protein function, subcellular localization, stability, and interactions. It is believed that up to 30% of all eukaryotic proteins may be phosphorylated.

During the last few years, phosphoproteomics have greatly improved due to the optimization of enrichment protocols for phosphoproteins and phosphopeptides, better fractionation techniques using chromatography, and improvement of mass spectrometry instrumentation. Thanks to these developments, it is now possible to analyze entire phosphorylation sets rapidly. However, protein and phosphorylation site identification by mass spectrometry is crucially dependent on the quality and completeness of the biological resource used for analysis.

In UniProtKB/Swiss-Prot, we make a special effort to document post- translational modifications and especially phosphorylation sites, using data from the literature. We have incorporated data from 38 high-quality phosphoproteomics studies which have allowed us to annotate or confirm 18,556 phosphorylation sites in 6,493 protein entries, mainly from human (45%), mouse (27%) and yeast (25%), but also from rat, Arabidopsis thaliana and bacteria. These high-throughput studies can be easily recognized among other UniprotKB references through the [LARGE SCALE ANALYSIS] tag appearing in 'cited for' topic in the 'References' section (RP line in the flat file).

Click here to obtain the complete list of UniProtKB/Swiss-Prot entries having at least one phosphorylation site found in proteomic studies.