PROJECT 3 Endocytosis and recycling of glycoconjugates are basic homeostatic mechanisms for controlling the turnover of many cell surface proteins, including signaling receptors, adhesion molecules, and membrane transporters. Many inherited human disorders affect the trafficking and turnover of glycoconjugates, leading to serious clinical manifestations. Impaired recycling and secondary storage of glycans is common in many of these diseases but the mechanisms that underlie this accumulation and the identity of the affected molecules are difficult to determine since few effective methods for targeted visualization and capture of glycoconjugates are currently available. The chemical reporter strategy is emerging as a versatile technology to visualize and capture glycoconjugates. While useful for tracking bulk glycoconjugate flux, the metabolic interconversion of glycosylation precursors from one form into another (as nucleotide sugars) and the broad dissemination of precursors into multiple glycan classes has limited the selectivity of metabolic labeling with modified precursors and hampered its ability to report changes in specific classes of glycoconjugates. Thus, there is an urgent need to develop new technologies for the selective labeling of specific glycoconjugate structures on intact cells. We propose to take advantage ofthe unprecedented availability of recombinant mammalian glycosyltransferases generated by the core of this program project and of our capacity to produce well-characterized, modified nucleotide sugars to selectively tag different classes of glycoconjugate glycans in disease and control cells. Our Selective Exo-Enzymatic Labeling strategy (SEEL) will provide us with the ability to track, capture, and identify subsets of cell surface glycoconjugates, revolutionizing the manner in which these molecules can be analyzed in the context of human disease. Once optimized, these SEEL tools will be employed to dissect the mechanisms that underlie altered glycoconjugate recycling and storage and identify the molecules whose cell surface localization or secretion are most affected. We will apply our innovative technological platform to investigate the contribution of glycan recycling/turnover mechanisms to the cellular pathophysiology of two human diseases characterized by altered glycoconjugate storage, Niemann-Pick disease type C (NPC) and mucopolysaccharidosis type IIIB (MPSIIIB), using cell types most relevant for the disease process (neural cells). SEEL-tagged glycoconjugates will also be employed to characterize the glycan and protein components of the glycoproteome of labeled cells, providing opportunities to further define glycosyltransferase specificity and to isolate sensitive molecules in disease-relevant cell types.
Impaired recycling and secondary storage of glycans is common in many inherited diseases but the mechanisms that underlie this accumulation and the identity ofthe affected molecules are difficult to determine since few effective methods for targeted visualization and capture of glycoconjugates are currently available. The proposed project will develop and apply technology that can track, capture, and identify subsets of cell surface glycoconjugates, revolutionizing the manner in which these molecules can be analyzed in the context of human disease.
|Jiang, Hao; López-Aguilar, Aimé; Meng, Lu et al. (2018) Modulating Cell-Surface Receptor Signaling and Ion Channel Functions by In?Situ Glycan Editing. Angew Chem Int Ed Engl 57:967-971|
|Epp, Alexandra; Hobusch, Juliane; Bartsch, Yannic C et al. (2018) Sialylation of IgG antibodies inhibits IgG-mediated allergic reactions. J Allergy Clin Immunol 141:399-402.e8|
|Lopez Aguilar, Aime; Meng, Lu; Hou, Xiaomeng et al. (2018) Sialyltransferase-Based Chemoenzymatic Histology for the Detection of N- and O-Glycans. Bioconjug Chem 29:1231-1239|
|Rouhanifard, Sara H; Lopez Aguilar, Aime; Meng, Lu et al. (2018) Engineered Glycocalyx Regulates Stem Cell Proliferation in Murine Crypt Organoids. Cell Chem Biol 25:439-446.e5|
|Kadirvelraj, Renuka; Yang, Jeong-Yeh; Sanders, Justin H et al. (2018) Human N-acetylglucosaminyltransferase II substrate recognition uses a modular architecture that includes a convergent exosite. Proc Natl Acad Sci U S A 115:4637-4642|
|Jensen, Jacob Krüger; Busse-Wicher, Marta; Poulsen, Christian Peter et al. (2018) Identification of an algal xylan synthase indicates that there is functional orthology between algal and plant cell wall biosynthesis. New Phytol 218:1049-1060|
|Voiniciuc, C?t?lin; Engle, Kristen A; Günl, Markus et al. (2018) Identification of Key Enzymes for Pectin Synthesis in Seed Mucilage. Plant Physiol 178:1045-1064|
|Moure, Maria J; Eletsky, Alexander; Gao, Qi et al. (2018) Paramagnetic Tag for Glycosylation Sites in Glycoproteins: Structural Constraints on Heparan Sulfate Binding to Robo1. ACS Chem Biol 13:2560-2567|
|Moremen, Kelley W; Ramiah, Annapoorani; Stuart, Melissa et al. (2018) Expression system for structural and functional studies of human glycosylation enzymes. Nat Chem Biol 14:156-162|
|Yu, Seok-Ho; Zhao, Peng; Prabhakar, Pradeep K et al. (2018) Defective mucin-type glycosylation on ?-dystroglycan in COG-deficient cells increases its susceptibility to bacterial proteases. J Biol Chem 293:14534-14544|
Showing the most recent 10 out of 42 publications