Bump-and-hole engineering identifies specific substrates of glycosyltransferases in living cells.
journal contributionposted on 2020-06-25, 14:04 authored by Benjamin Schumann, Stacy Alyse Malaker, Simon Peter Wisnovsky, Marjoke Froukje Debets, Anthony John Agbay, Daniel Fernandez, Lauren Jan Sarbo Wagner, Liang Lin, Zhen Li, Junwon Choi, Douglas Michael Fox, Jessie Peh, Melissa Anne Gray, Kayvon Pedram, Jennifer Jean Kohler, Milan Mrksich, Carolyn Ruth Bertozzi
Studying posttranslational modifications classically relies on experimental strategies that oversimplify the complex biosynthetic machineries of living cells. Protein glycosylation contributes to essential biological processes, but correlating glycan structure, underlying protein, and disease-relevant biosynthetic regulation is currently elusive. Here, we engineer living cells to tag glycans with editable chemical functionalities while providing information on biosynthesis, physiological context, and glycan fine structure. We introduce a non-natural substrate biosynthetic pathway and use engineered glycosyltransferases to incorporate chemically tagged sugars into the cell surface glycome of the living cell. We apply the strategy to a particularly redundant yet disease-relevant human glycosyltransferase family, the polypeptide N-acetylgalactosaminyl transferases. This approach bestows a gain-of-chemical-functionality modification on cells, where the products of individual glycosyltransferases can be selectively characterized or manipulated to understand glycan contribution to major physiological processes.