Recently discovered PTM may be surprisingly common.
O-GlcNAc-6-phosphate is a recently discovered PTM that was previously only identified on a single protein found in rat neurons. A paper this month in MCP from Hannes Hahne and Bernard Kuster demonstrates that this modification is a whole lot more common. By tracing specific reporter ions produced by the degradation of the mod during CID, they were able to confirm the presence of this modification on a number of different mouse neuronal proteins. They also confirm that this modification is found on some human proteins.