TAILIEUCHUNG - Báo cáo khoa học: Elements of the C-terminal t peptide of acetylcholinesterase that determine amphiphilicity, homomeric and heteromeric associations, secretion and degradation

The C-terminal t peptide (40 residues) of vertebrate acetyl-cholinesterase (AChE) T subunits possesses a series of seven conserved aromatic residues and forms an amphiphilic a-helix; it allows the formation of homo-oligomers (mono-mers, dimers and tetramers) and heteromeric associations with the anchoringproteins, ColQ and PRiMA, which contain a proline-rich motif (PRAD). We analyzed the influenceofmutations in the t peptideofTorpedoAChETon oligomerization and secretion. | Eur. J. Biochem. 271 1476-1487 2004 FEBS 2004 doi Elements of the C-terminal t peptide of acetylcholinesterase that determine amphiphilicity homomeric and heteromeric associations secretion and degradation Stephanie Belbeoc h Cinzia Falasca Jacqueline Leroy Annick Ayon Jean Massoulie and Suzanne Bon Laboratoire de Neurobiologie Cellulaire et Moléculaire CNRS UMR 8544 Ecole Normale Superieure Paris France The C-terminal t peptide 40 residues of vertebrate acetylcholinesterase AChE T subunits possesses a series of seven conserved aromatic residues and forms an amphiphilic a-helix it allows the formation of homo-oligomers monomers dimers and tetramers and heteromeric associations with the anchoring pi mems. CoIQ add PRiMA. which contain a proline-rich motif PPAD . We analyzed the influence of mutations in the t peptide of Torpedo AChET on oligomerization and secretion. Charged residues influenced the distribution of homo-oligomers but had little effect on the heteromeric association with QN a PPAD-containing N-terminal fragment of ColQ. The formation of homotetramers and QN-linked tetramers required a central core of four aromatic residues and a peptide segment extending to residue 31 the last nine residues 32-40 were not necessary although the formation of disulfide bonds by cysteine C37 stabilized T4 and T4-QN tetramers. The last two residues of the t peptide EL induced a partial intracellular retention replacement of the C-terminal CAEL tetrapeptide by KDEL did not prevent tetramerization and heteromeric association with Qn indicating Amt de asrociatians talce plare in the endoplasmic reticulum. Mutations that disorganize the a-helical structure of the t peptide were found to enhance degradation. Co-expression with QN generally increased secretion mostly as T4-QN complexes but reduced it for some mutants. Thus mutations in this small autonomous interaction domain bring mfomtatíon on the étatuées that determine oligomeric .

• Báo cáo khoa học
• Report medicine
• traditional medicine
• scientific reports
• gastric cancer
• hormone medicine
• tumor cells
• medical knowledge
• medical research
• analysis of cytoplasmic
• oxidation
• Crystal structure
• bacteria
• hemoglobin
• medicine
• cell proliferation
• breast cancer
• chemical reaction
• biochemical studies
• environmental medicine