1National Key Laboratory of Medical Molecular Biology, Department of Pathophysiology, Institute of Basic Medical Sciences Chinese Academy of Medical Sciences, School of Basic Medicine Peking Union Medical College, Beijing, China
2State Key Laboratory of Molecular and Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China
3Department of Biochemistry and Molecular Biology, Gene Engineering and Biotechnology Beijing Key Laboratory, Beijing Normal University, Beijing, China
This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, reproduction and adaptation in any medium and for any purpose provided that it is properly attributed. For attribution, the original author(s), title, publication source (PeerJ PrePrints) and either DOI or URL of the article must be cited.
Urine, by accumulating all kinds of changes, was proposed to be a better source for biomarker discovery. As one of the most common post-translational modifications, phosphorylation plays a vital role in many biological activities. However, the urine phosphoproteome has been largely neglected due to the low abundance of phosphoproteins and the presence of various phosphatases in urine. The low level of background phosphorylation in urine is actually advantageous, as urinary phosphopeptides/proteins that are stable to the phosphatases present in urine have the potential to serve as valuable disease biomarkers. Using a TiO2 enrichment strategy, this study aimed to create a comprehensive proteomic profile of human urinary phosphoproteins and to characterize the changes in the urine phosphoproteome after incubation of urine with cell lysates. In total, 106 urine phosphorylation sites corresponding to 64 proteins, including 80 previously unidentified human urine protein phosphorylation sites, were identified by mass spectrometry. Fifteen phosphopeptides, together averaging 47% of the total phosphopeptides, were found in samples from three individuals. Addition of cellular proteins to urine did not significantly change the phosphorylation level of urine proteins. But there were still a few phosphopeptides from cell lysates survived urinary phosphatases; such phosphopeptides represent potential biomarkers in urine.
This is a submission to PeerJ for review. Realization and emphasis of change as the most fundamental property of biomarker, urine, by accumulating all kinds of changes, was proposed to be a better source for biomarker discovery. The urine proteome has been commonly used in discovering biomarkers of renal, bladder and prostate diseases. As one of the most common post-translational modifications, phosphorylation play vital roles in many biological activities. However, the urine phosphoproteome has been largely neglected due to the low abundance of phosphoproteins and the presence of various phosphatases in urine. But we believe the low level of background phosphorylation in urine is actually advantageous, as urinary phosphopeptides and proteins that are able to survive the phosphatases present in urine can potentially serve as valuable disease biomarkers.
Phosphorylation sites identified in this study and their clinical uses
"Following" is like subscribing to any updates related to a preprint.
These updates will appear in your home dashboard each time you visit PeerJ.
You can also choose to receive updates via daily or weekly email digests.
If you are following multiple preprints then we will send you
no more than one email per day or week based on your preferences.
Note: You are now also subscribed to the subject areas of this preprint
and will receive updates in the daily or weekly email digests if turned on.
You can add specific subject areas through your profile settings.