Identification and characterization of phosphorylated proteins in the human pituitary.
Post-translational modifications of proteins from the human pituitary gland play an important role in the regulation of different body functions. We report on the application of a liquid chromatography-tandem mass spectrometry (MS/MS) based approach to detect and characterize phosphorylated proteins in a whole human pituitary digest. By combining an immobilized metal affinity column-based enrichment method with MS/MS conditions that favor the neutral loss of phosphoric acid from a phosphorylated precursor ion, we identified several previously undescribed phosphorylated peptides. The identified peptides were matched to the sequences of six pituitary proteins: the human growth hormone, chromogranin A, secretogranin I, 60S ribosomal protein P1 and/or P2, DnaJ homolog subfamily C member 5, and galanin. The phosphorylation sites of these important regulatory proteins were determined by MS/MS and MS(3) analysis.
The Charles B. Stout Neuroscience Mass Spectrometry Laboratory, University of Tennessee Health Science Center, Memphis, 38163, USA.
Francesco
F
Giorgianni
Sarka
S
Beranova-Giorgianni
Dominic M
DM
Desiderio
D000595:Amino Acid Sequence; D053379:Chromogranin A; D002864:Chromogranins / Q000737:chemistry; D019992:Databases as Topic; D019004:Galanin / Q000737:chemistry; D019382:Human Growth Hormone / Q000737:chemistry; D006801:Humans; D007477:Ions; D013058:Mass Spectrometry / Q000379:methods*; D008969:Molecular Sequence Data; D010455:Peptides / Q000737:chemistry; D010748:Phosphopeptides / Q000737:chemistry; D010766:Phosphorylation; D010902:Pituitary Gland / Q000378:metabolism*; D011499:Protein Processing, Post-Translational; D013997:Time Factors; D014357:Trypsin / Q000737:chemistry
D053379:Chromogranin A; D002864:Chromogranins; D007477:Ions; D010455:Peptides; D010748:Phosphopeptides; D019382:Human Growth Hormone; D019004:Galanin; D014357:Trypsin