Journal Article

Protein O-Mannosylation in the Murine Brain: Occurrence of Mono-O-Mannosyl Glycans and Identification of New Substrates

Liu, Yan, Feizi, Ten, Yu, Jin, Strahl, Sabine, Möhrlen, Frank, Hu, Huaiyu, Lommel, Mark, Bartels, Markus F., Westerlind, Ulrika, Ruppert, Thomas, Winterhalter, Patrick R.

2016

Overview

Protein O-mannosylation is a post-translational modification essential for correct development of mammals. In humans, deficient O-mannosylation results in severe congenital muscular dystrophies often associated with impaired brain and eye development. Although various O-mannosylated proteins have been identified in the recent years, the distribution of O-mannosyl glycans in the mammalian brain and target proteins are still not well defined. In the present study, rabbit monoclonal antibodies directed against the O-mannosylated peptide YAT(α1-Man)AV were generated. Detailed characterization of clone RKU-1-3-5 revealed that this monoclonal antibody recognizes O-linked mannose also in different peptide and protein contexts. Using this tool, we observed that mono-O-mannosyl glycans occur ubiquitously throughout the murine brain but are especially enriched at inhibitory GABAergic neurons and at the perineural nets. Using a mass spectrometry-based approach, we further identified glycoproteins from the murine brain that bear single O-mannose residues. Among the candidates identified are members of the cadherin and plexin superfamilies and the perineural net protein neurocan. In addition, we identified neurexin 3, a cell adhesion protein involved in synaptic plasticity, and inter-alpha-trypsin inhibitor 5, a protease inhibitor important in stabilizing the extracellular matrix, as new O-mannosylated glycoproteins.

• Publisher: Public Library of Science,Public Library of Science (PLoS)
• Subject: Amino Acid Sequence / Animals / Biological Transport / Biology and Life Sciences / Brain / Brain - cytology / Brain - metabolism / Breast cancer / Cadherins / Cell adhesion / Cell adhesion & migration / Chondroitin sulfate / Chromatography / College campuses / Congenital diseases / Extracellular matrix / GABAergic Neurons - metabolism / Glycoproteins / Glycoproteins - chemistry / Glycoproteins - metabolism / Identification / Laboratories / Mammals / Mannose / Mannose - metabolism / Mass spectrometry / Mass spectroscopy / Medicine and Health Sciences / Mice / Molecular biology / Monoclonal antibodies / Monosaccharides / Muscular dystrophy / Neurocan / Neurons / Neurosciences / Peptides / Physical Sciences / Physiology / Polysaccharides / Polysaccharides - chemistry / Polysaccharides - metabolism / Post-translation / Post-translational modifications / Protease inhibitors / Proteases / Protein Processing, Post-Translational / Proteinase inhibitors / Proteins / Proteomics / Research and Analysis Methods / Scientific imaging / Substrates / Synaptic plasticity / Trypsin / Trypsin inhibitors / γ-Aminobutyric acid