22 May 2017

New publication in Journal of Biological Chemistry

We recently discovered that the cadherin superfamily carries O-linked mannose (O-Man) glycans at highly conserved residues in specific extracellular cadherin domains, and it was suggested that the function of E-cadherin was dependent on the O-Man glycans. In order to explore the functions of O-Man glycans on cadherins and protocadherins we used a combinatorial gene editing strategy in multiple cell lines to evaluate the role of the two POMTs initiating O-Man glycosylation and the major enzyme elongating O-Man glycans, the protein O-mannose β-1,2-N-acetylglucosaminyltransferase, POMGnT1. Surprisingly, O-mannosylation of cadherins and protocadherins do not require POMT1 and/or POMT2 in contrast to -dystroglycan, and moreover the O-Man glycans on cadherins are not elongated. Thus, the classical and evolutionary conserved POMT O-mannosylation pathway is essentially dedicated to -dystroglycan and a few other proteins, while a novel O-mannosylation process in mammalian cells is predicted to serve the large cadherin superfamily and other proteins.

Larsen, ISB, Narimatsu Y, Joshi HJ, Yang Z, Harrison OJ, Brasch J, Shapiro L, Honig B, Vakhrushev SY, Clausen H, Halim A (2017): Mammalian O-mannosylation of Cadherins and Plexins is Independent of Protein O-mannosyltransferase 1 and 2. J Biol Chem (epub ahead of print)

Read about the publication in the UCPH Health Newsletter