Luk_2012_Febs.J_279_3229

Acetylcholinesterase AChE is well-known for its cholinergic functions in the nervous system however this enzyme is also found in other tissues where its function is still not understood AChE is synthesized through alternative splicing as splicing variants with isoforms including read-through AChE(R tailed AChE(T and hydrophobic AChE(H In human erythrocytes AChE(H is a glycophosphatidylinositol-linked dimer on the plasma membrane Three N-linked glycosylation sites have been identified in the catalytic domain of human AChE Here we investigate the roles of glycosylation in assembly and trafficking of human AChE(H In transfected fibroblasts expression of AChE(H was able to mimic the function of the dimeric form of AChE on the erythrocyte membrane A glycan-depleted form was constructed by site-directed mutagenesis By comparison with the wild-type AChE(H the mutant had a much lower enzymatic activity and a much higher K(m value In addition the mutant was dimerized in the endoplasmic reticulum but was not trafficked to the Golgi apparatus The results suggest that the glycosylation may affect AChE(H enzymatic activity and trafficking but not dimer formation The present findings indicate the significance of N-glycosylation in controlling the biosynthesis of the AChE(H dimer form Structured digital abstract AChE-H and GM130 colocalize by cosedimentation through density gradient View interaction AChE-H and Calnexin colocalize by cosedimentation through density gradient View interaction).