Table I

O-GlcNAc-modified peptides identified from a mouse brain postsynaptic density preparation

A “g” following a serine or threonine denotes specific localization of O-GlcNAc to that site (when underlined) or localization of O-GlcNAc to one of several possible sites if not underlined. Amino acids in bold font correspond to the shared motifs PVST or TTA (in italics). All peptides are singly O-GlcNAc-modified unless otherwise noted in parentheses after the sequence. Exact localization of modification site by ECD and/or BEMAD or enhancement of peptide sequencing by MS3 is noted by “X.”

ProteinAccession no.Mascot scorePeptide sequence(s)MS3ECDBEMAD
Tubulin polymerization-promoting protein Q7TQD2 36APVISgGVTK
Shank 2 Q80238 64SPEVMSTgVSGTRXX
29SPEVMSgTgVSgGTgR (two O-GlcNAc sites)X
Synaptopodin Q8CC35 74VSAPPSgAASgTFSgRX
Spectrin β2 Q5SQL8 53HDTSASTQSTPASSgRX
Catenin-δ2 O35927 58TSgTgAPSgSgPGVDSgVPLQRX
Neurofilament triplet L P08551 94SAYSSYSAPVSgSgSgLSgVRX
Synaptic Ras-GTPase-activating protein 1Q9QUH6 (rat)40QHSgQTgPSgTgLNPTMPASgER
EMSY protein Q8BMBO 25AVVPVSgK
Sickle tail Q75UV8 34LSSLPVSgRX
Myocardin-related transcription factor B P59759 49SgTgAPVLPTNTVSSAKX
Ponsin Q62417 77TPVDYIDLPYSgSgSgPSRX
Neurofilament triplet M gi‖128150 25GSPSgTgVSgSgSgYKR
24QPSgVTgISSK
Internexin gi‖34328368 26ILSgSgTgASgK
Host cell factor C1 (HCF1) P51611 52SgPITgIITgTgKX
26SgPITgIITgTgKVMTgSgGTgGAPAK
Ankyrin Ggi‖3885972 (rat)35SgAADVISTAKXX
44STLGASgTgTgSgSgVKX
29VPTgITgEATgPIK
33SIWSVSgTgPSgPIK
26TSgPVTgTgAGSgLLER (two O-GlcNAc sites)X
44ALSTgTTAMPFSPLRXX
22TgSgPVTgTgAGSgLLERX
Synapsin 1 O88935 67LPSPTAAPQQSASQATPVTgQGQGRX
70QTgTAAAAATFSEQVGGGSGGAGRX
20ASQATPVTgQGQGRXX
Piccolo Q9QYX7 68SCTAQQPATgTgLPEDRXX
20QTgTANEVYRX
26SgPSgGGLPVSgTgHPSgK
24TTGPYPETgRXX
76VSgTGEVMDYSSKXX
79QVISGVGISTPQYSgTgARX
20RQTgTANEVYRRX
38RQTgTANEVYRXX
40NAFDYSgGGTgEAAVDLTgSgGR
30SgVSgIPIPPEPLALDRX
61DLSgGIHTgTgDAITgSgLSgALHQSgQPMPR
Bassoon O88737 35IAVAGTgEGPGQPRX
25SQGPGSPATTgASPTR
34QLLPSgTgATgVR (two O-GlcNAc sites)X
39HSgDSgGSgDSgKHDATASgSgSgTgTgAAATgAR
43GLAGPTTVPATgKXX
62KYGLALDPVSgGR
32YSgSgVSgNIYSDHR
35SVTgDTALPGQSSGPFYSPRXX
106GDAVGFQEASgLAQYSgATgTgARX
48LQPQSgQPTgTgRX
40ISgSgVPGTSgRX
47HSgYSgLGFADGRX
40LLDTgSgFASgSgERX
53HPTgDLLSgHPLPLR
52VSPAIHITgAATDPKXX
92HDATASSSTgTgAAATgARXX
65LHSSyPVSgSgTgLTSgKX
47GYMTPTSgPAGSgERX
45EEPFSTTgAPAVIKXX
77ATgAEFSgTgQTgPSgLTgLSgSgDIPR
58QLLPSgTgATgVRX
91HGSgGSgGGPDLVQYQPQHGPGLSgAPQGLAPLR
77EVGMTgFSgQGPGSgPATgTgASgPTR (two O-GlcNAc)
40EEPFSgTgTgAPAVIK (two O-GlcNAc sites)XX
37SgSgVSgQSgPAPTgYPSgDSgHYTSgLEQNVPR
83SgPSgTgSgSgTIHSgYGQPPTTANYGSQTEELPHAPSGPPGSGR
30SQGPGSPATgTgASgPTgR (two O-GlcNAc)