title: N-linked glycosylation of proline-rich membrane anchor (PRiMA) is not required for assembly and trafficking of globular tetrameric acetylcholinesterase.
abstract: Acetylcholinesterase (AChE) is organized into globular tetramers (G(4)) by a structural protein called proline-rich membrane anchor (PRiMA), anchoring it into the cell membrane of neurons in the brain. The assembly of AChE tetramers with PRiMA requires the presence of a C-terminal "t-peptide" in the AChE catalytic subunit (AChE(T)). The glycosylation of AChE(T) is known to be required for its proper assembly and trafficking; however, the role of PRiMA glycosylation in the oligomer assembly has not been revealed. PRiMA is a glycoprotein containing two putative N-linked glycosylation sites. By using site-directed mutagenesis, the asparagine-43 was identified to be the N-linked glycosylation site of PRiMA. Abolishing glycosylation on mouse PRiMA appeared not to affect its assembly with AChE(T), the enzymatic properties of AChE, and the membrane trafficking of PRiMA-linked AChE tetramers. This result is contrary to the reports that glycosylation is essential for conformation and trafficking of membrane glycoproteins.
authors: Division of Life Science, Center for Chinese Medicine and State Key Laboratory of Molecular Neuroscience, The Hong Kong University of Science and Technology, Clear Water Bay Road, Hong Kong Special Administrative Region.
authors: Wallace K B
authors: WK
authors: Chan
authors: Vicky P
authors: VP
authors: Chen
authors: Wilson K W
authors: WK
authors: Luk
authors: Roy C Y
authors: RC
authors: Choi
authors: Karl W K
authors: KW
authors: Tsim
mesh_terms: D000110:Acetylcholinesterase / Q000737:chemistry* / Q000378:metabolism*; D000818:Animals; D019281:Dimerization; D006031:Glycosylation; D057809:HEK293 Cells; D006801:Humans; D008565:Membrane Proteins / Q000737:chemistry* / Q000378:metabolism*; D051379:Mice; D046912:Multiprotein Complexes / Q000737:chemistry / Q000378:metabolism; D009419:Nerve Tissue Proteins / Q000737:chemistry* / Q000378:metabolism*; D011485:Protein Binding / Q000502:physiology; D021381:Protein Transport
chemical_list: D008565:Membrane Proteins; D046912:Multiprotein Complexes; D009419:Nerve Tissue Proteins; C446290:PRIMA1 protein, human; D000110:Acetylcholinesterase