Krejci E, Thomine S, Boschetti N, Legay C, Sketelj J, Massoulié J
Laboratoire de Neurobiologie Cellulaire et Moléculaire, CNRS URA 1857, Ecole Normale Supérieure, Paris, France.
J Biol Chem. 1997 Sep 5;272(36):22840-7. doi: 10.1074/jbc.272.36.22840.
The collagen-tailed or asymmetric forms (A) represent a major component of acetylcholinesterase (AChE) in the neuromuscular junction of higher vertebrates. They are hetero-oligomeric molecules, in which tetramers of catalytic subunits of type T (AChET) are attached to the subunits of a triple-stranded collagen "tail." We report the cloning of a rat AChE-associated collagen subunit, Q. We show that collagen tails are encoded by a single gene, COLQ. The ColQ subunits form homotrimers and readily form collagen-tailed AChE, when coexpressed with rat AChET. We found that the same ColQ subunits are incorporated, in vivo, in asymmetric forms of both AChE and butyrylcholinesterase. A splice variant from the COLQ gene encodes a proline- rich AChE attachment domain without the collagen domain but does not represent the membrane anchor of the brain tetramer. The COLQ gene is expressed in cholinergic tissues, brain, muscle, and heart, and also in noncholinergic tissues such as lung and testis.
胶原尾型或不对称型（A）是高等脊椎动物神经肌肉接头中乙酰胆碱酯酶（AChE）的主要成分。它们是异源寡聚体分子，其中T型催化亚基（AChET）的四聚体与三链胶原“尾”的亚基相连。我们报道了大鼠AChE相关胶原亚基Q的克隆。我们发现胶原尾由单个基因COLQ编码。当与大鼠AChET共表达时，ColQ亚基形成同三聚体并易于形成胶原尾型AChE。我们发现相同的ColQ亚基在体内整合到AChE和丁酰胆碱酯酶的不对称形式中。COLQ基因的一个剪接变体编码一个富含脯氨酸的AChE附着结构域，但没有胶原结构域，且不代表脑四聚体的膜锚定物。COLQ基因在胆碱能组织、脑、肌肉和心脏中表达，也在非胆碱能组织如肺和睾丸中表达。
