PMID: 22750213

 

    Legend: Sugar

Title : N-linked glycosylation of proline-rich membrane anchor ( PRiMA ) is not required for assembly and trafficking of globular tetrameric acetylcholinesterase

Abstract :

1. 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
2. The assembly of AChE tetramers with PRiMA requires the presence of a C-terminal "t-peptide" in the AChE catalytic subunit ( AChE ( T ))
3. 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
4. PRiMA is a glycoprotein containing two putative N-linked glycosylation sites
5. By using site-directed mutagenesis, the asparagine-43 was identified to be the N-linked glycosylation site of PRiMA
6. 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
7. This result is contrary to the reports that glycosylation is essential for conformation and trafficking of membrane glycoproteins