期刊
JOURNAL OF PROTEOME RESEARCH
卷 10, 期 6, 页码 2725-2733出版社
AMER CHEMICAL SOC
DOI: 10.1021/pr1011153
关键词
AP180; glycosyl phosphorylation; N-acetylglucosamine phosphorylation; synaptic vesicle endocytosis; phosphorylation; graphite; mass spectrometry; nerve terminals
资金
- Mizutani Foundation for Glycoscience
- Australian Research Council
- National Health and Medical Research Council of Australia
- Danish Council for Independent Research Natural Sciences
- Danish Agency for Science, Technology and Innovation
- Ian Potter Foundation
- Cancer Institute New South Wales
Protein phosphorylation and glycosylation are the most common post-translational modifications observed in biology, frequently on the same protein. Assembly protein AP180 is a synapse-specific phosphoprotein and O-linked beta-N-acetylglucosamine (O-GlcNAc) modified glycoprotein. AP180 is involved in the assembly of clathrin coated vesicles in synaptic vesicle endocytosis. Unlike other types of O-glycosylation, O-GlcNAc is nucleocytoplasmic and reversible. It was thought to be a terminal modification, that is, the O-GlcNAc was not found to be additionally modified in any way. We now show that AP180 purified from rat brain contains a phosphorylated O-GlcNAc (O-GlcNAc-P) within a highly conserved sequence. O-GlcNAc or O-GlcNAc-P, but not phosphorylation alone, was found at Thr-310. Analysis of synthetic GlcNAc-6-P produce. identical fragmentation products to GlcNAc-P from AP180. Direct O-linkage of GlcNAc-P to a Thr residue was confirmed by electron transfer dissociation MS. A second AP180 tryptic peptide was also glycosyl phosphorylated, but the site of modification not assigned. Sequence similarities suggest there maybe a common motif within AP180 involving glycosyl phosphorylation and dual. flanking phosphorylation sites within 4 amino acid residues. This novel type of protein glycosyl phosphorylation adds a new signaling mechanism to the regulation of neurotransmission and more complexity to the study of O-GlcNAc modification.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据