The diverse biological roles of glycoconjugates
Glycoconjugates play critical roles in recognition, adhesion, protein stability and function. Alterations in glycosylation frequently lead to disease. The four sessions in the 1012 annual meeting’s glycobiology theme focus on the role of glycoconjugates in pathogenesis, signaling, development, metabolism and disease. They also address novel metabolic routes of glycoconjugate assembly.
Glycoconjugates often provide the key interface between a microbial pathogen and a host cell and are, therefore, excellent targets for the development of therapeutics. The first session, “Glycoconjugates in Pathogen Invasion and Virulence,” features three talks that focus on the surface glycoconjugates of bacteria and a protozoan parasite.
Malcolm McConville (University of Melbourne) will highlight recent advances in our understanding of cell-wall assembly in mycobacteria. The cell walls of these important pathogens are composed of several classes of glycolipids, and a number of novel proteins have been shown to regulate their assembly and transport across the cell membrane.
Lora Hooper (University of Texas Southwestern Medical Center at Dallas) will present her work on the innate immune mechanisms that promote symbiotic relationships with the vast communities of bacteria that inhabit the intestine. She will focus on the role of a secreted carbohydrate-binding protein in maintaining the mutually beneficial nature of these host-microbial interactions.
Igor Almeida (University of Texas at El Paso) has identified glycoconjugates of the Chagas-disease-causing parasite Trypanosoma cruzi that are virulence factors. He will describe recent efforts to use these glycoconjugates as targets for vaccine development.
Signaling and development
The second session, “Role of Glycoconjugates in Signaling and Development,” further highlights the diverse roles of glycoconjugates in biology. David Levin (Boston University Goldman School of Dental Medicine) will present recent work on the cell-wall-integrity signaling mechanisms that enable yeast cells to respond to cell-wall stress.
Hannes Buelow (Albert Einstein College of Medicine) will describe his studies of the role of heparan sulfate proteoglycans in axon guidance and nervous-system development in the model organism Caenorhabditis elegans.
Thomas Biederer (Yale University) will talk about his work on the SynCAM family of adhesion molecules and the role that glycans play in regulating adhesion mediated by these proteins and subsequent synapse development.
Although the assembly of glycoconjugates from activated monosaccharides is generally understood, there remain numerous gaps in our knowledge. In the third session, “Novel Metabolic Routes of Glycoconjugate Assembly,” Karen Colley (University of Illinois College of Medicine) will discuss the biosynthesis of polysialic acid, a unique antiadhesive glycoconjugate found on only a few proteins that play roles in the development and function of the nervous and immune systems. She will present new data that illustrate how these proteins are selected for polysialylation.
Debra Mohnen (University of Georgia) will discuss the assembly of pectin, a major plant cell-wall polysaccharide, which functions in plant growth, development, and response to pathogens and symbionts and has diverse positive effects on human health. She will describe new results describing novel mechanisms that regulate pectin synthesis and cell-wall assembly.
A key feature of the assembly of many glycoconjugates is the transbilayer movement of lipid biosynthetic intermediates. Anant Menon (Weill Cornell Medical College) will discuss recent efforts to identify the enigmatic flippases required for moving these complex glycolipid structures across the membrane bilayer.
Glycoconjugates in metabolism and disease
In the final session, “Role of Glycoconjugates in Metabolism and Disease,” Jeff Esko (University of California, San Diego) will discuss his work on endothelial cell receptors and their interaction with heparan sulfate with respect to innate immunity.
John Hanover (National Institutes of Health) will describe his group’s studies on the role of nutrient-driven O-GlcNAc in regulating gene expression by modulating higher-order chromatin structure and the multifaceted histone code. His results suggest that O-GlcNAc directly regulates RNA polymerase II and may contribute to transgenerational epigenetic reprogramming.
Lance Wells (University of Georgia) will speak on the role of O-mannosylation in congenital muscular dystrophy, cancer metastasis and arenavirus entry into cells. He will present data that highlight the novel protein substrates for O-mannosylation, as well as the enzymes and the novel glycans they synthesize that are disrupted in various pathophysiologies.
Karen Colley (firstname.lastname@example.org) is a professor at the University of Illinois College of Medicine, and Anant K. Menon (email@example.com) is a professor at Weill Cornell Medical College.