Multi-glycomic characterization of cell membrane and the role of glycans in protein-protein interactions

Aberrant glycosylation is a hallmark of diseases from cancer to infection. Identifying the changes in glycosylation provide potentially new biomarkers as well as targets for therapeutic interventions. This research involves a number of projects that will (1) automate the glycomic analysis, (2) identify the enzymes involved in their synthesis, and (3) reveal the role of the specific structures in protein-protein and protein-lipid interactions. We will develop a platform that combines comprehensive glycomic analysis while employing automated sample preparation to provide profiles of N- and O-glycans on proteins and on glycolipids. We will simultaneously develop software for automated structural annotation yielding linkages and other structural features that are typically not readily obtainable. These structures (N- and O-glycans) will contain more than the putative structures commonly obtained based on compositions but will also contain linkages of important components such as sialic acids and fucoses. The glycomic profiles will then be combined with transcriptomic data of the same cells and using regression algorithms determine the pathways for the step-by-step synthesis of each individual glycan. The pathway analysis will identify key synthetic points and enzymes that may be targeted to alter specific glycans for therapeutic interventions. We will then determine how the functions of the protein are affected by the glycomic changes using newly developed crosslinking strategies. These crosslinkers are significantly improved to be quantitative revealing the uniquely interacting protein networks with the associated glycans. The combined workflows will be employed to probe the nature of insulin resistance in cell lines. We will determine how protein glycosylation differs in different cells, obtain their glycomic profile and induce insulin resistance and observe how protein-protein interactions are altered in the protein networks of the cell membrane. This research will provide a greater fundamental understanding of the nature of glycan structures and site heterogeneity and how they affect cellular functions. The proposal is an attempt to convert a longstanding NIH grant (R01GM049077) now in its 30th year to the MIRA program. Project Number: 1R35GM161759-01 | Fiscal Year: 2026 | NIH Institute/Center: National Institute of General Medical Sciences (NIGMS) | Principal Investigator: CARLITO LEBRILLA | Institution: UNIVERSITY OF CALIFORNIA AT DAVIS, DAVIS, CA | Award Amount: $402,051 | Activity Code: R35 | Study Section: Special Emphasis Panel[ZRG1 MCST-G (56)] View on NIH RePORTER: https://reporter.nih.gov/project-details/11260736