Interrelations between assembly and secretion of recombinant human acetylcholinesterase.

摘要: Transport and secretion of recombinant human acetylcholinesterase (rHuAChE) were studied in transfected 293 cells expressing either the oligomerized soluble enzyme or a monomeric mutant derivative which Cys-580 was substituted by alanine (C580A). In wild-type enzyme, gradual assembly newly synthesized intracellular rHuAChE monomers into oligomers occurs within endoplasmic reticulum. Secretion mature medium is efficient appears to be exclusive multimeric forms. Consistently, oligomers, but not monomers, are endoglycosidase H-resistant, indicating that only undergo terminal glycosylation enzyme. contrast, dimerization-defective C580A mutant, secreted as efficiently multimers. No significant difference between transport rates revealed probing with specific lectins. both systems, processing prior trans-Golgi galactosylation compartment appear rate-limiting, whereas following passage cell surface rapid. conclusion, we suggest presence free cysteine at COOH terminus polypeptide, effectuated, its absence, exported from reticulum capable traversing entire secretory pathway.