The objectives of this project are: (1) the development of chemical tools for fundamental studies of O-linked glycosylation, and (2) the identification of glycoprotein cancer biomarkers. Mucin-type O-linked glycosylation is a posttranslational modification of membrane and secreted proteins in higher eukaryotes. Its functions are poorly understood, but altered mucin-type O-linked glycosylation has been correlated with cancer growth and metastasis. Chemical tools are needed both for perturbing and detecting O-linked glycosylation on proteins and cells. The first major goal of this renewal application is to develop small molecule inhibitors of mucin-type O-linked glycosylation by targeting the polypeptide N-acetylgalactosaminyltransferases (ppGalNAcTs) and UDP-GlcNAc/GalNAc C4-epimerase (GALE), enzymes that are required for O-glycan biosynthesis. The inhibitors will be used to probe the importance of O-linked glycans in tumor growth and metastasis. The second goal is to develop a chemical approach for rapid profiling of changes in mucin-type O-linked glycosylation associated with cancer. The approach involves metabolic labeling of O-linked glycoproteins within living animals using an azido analog of N-acetylgalactosamine (termed GalNAz). The labeled glycoproteins from serum and tissue samples will be chemically tagged with phosphine probes via Staudinger ligation, permitting their detection and identification using proteomic methods. Comparison of labeled species from normal and tumor-bearing mice may reveal new serum biomarkers of disease. The final goal is to develop an analogous method for detection of protein O-fucosylation, a recently discovered form of O-linked glycosylation with mysterious functions. Cell-surface sugars are known to participate in many normal and disease processes, but have not yet been exploited as targets for drugs or clinical diagnostics. This research will advance our understanding of the roles cell-surface sugars play in tumor growth and metastasis. The chemical tools developed in this project may produce a new generation of anti-cancer drugs and new clinical tests for early diagnosis.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
5R01GM066047-08
Application #
7796761
Study Section
Synthetic and Biological Chemistry A Study Section (SBCA)
Program Officer
Fabian, Miles
Project Start
2002-08-01
Project End
2011-09-05
Budget Start
2010-05-01
Budget End
2011-09-05
Support Year
8
Fiscal Year
2010
Total Cost
$308,691
Indirect Cost
Name
University of California Berkeley
Department
Chemistry
Type
Schools of Arts and Sciences
DUNS #
124726725
City
Berkeley
State
CA
Country
United States
Zip Code
94704
Palaniappan, Krishnan K; Bertozzi, Carolyn R (2016) Chemical Glycoproteomics. Chem Rev 116:14277-14306
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Belardi, Brian; de la Zerda, Adam; Spiciarich, David R et al. (2013) Imaging the glycosylation state of cell surface glycoproteins by two-photon fluorescence lifetime imaging microscopy. Angew Chem Int Ed Engl 52:14045-9
Palaniappan, Krishnan K; Hangauer, Matthew J; Smith, Timothy J et al. (2013) A chemical glycoproteomics platform reveals O-GlcNAcylation of mitochondrial voltage-dependent anion channel 2. Cell Rep 5:546-52
Breidenbach, Mark A; Palaniappan, Krishnan K; Pitcher, Austin A et al. (2012) Mapping yeast N-glycosites with isotopically recoded glycans. Mol Cell Proteomics 11:M111.015339
Yu, Seok-Ho; Boyce, Michael; Wands, Amberlyn M et al. (2012) Metabolic labeling enables selective photocrosslinking of O-GlcNAc-modified proteins to their binding partners. Proc Natl Acad Sci U S A 109:4834-9
An, Hyun Joo; Gip, Phung; Kim, Jaehan et al. (2012) Extensive determination of glycan heterogeneity reveals an unusual abundance of high mannose glycans in enriched plasma membranes of human embryonic stem cells. Mol Cell Proteomics 11:M111.010660
Boyce, Michael; Bertozzi, Carolyn R (2011) Bringing chemistry to life. Nat Methods 8:638-42
Hubbard, Sarah C; Boyce, Michael; McVaugh, Cheryl T et al. (2011) Cell surface glycoproteomic analysis of prostate cancer-derived PC-3 cells. Bioorg Med Chem Lett 21:4945-50

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