Evidence for a new member of the myosin I family from mammalian brain.
Evidence for a new member of the myosin I family from mammalian brain.
复制标题
来自哺乳动物大脑的肌球蛋白 I 家族新成员的证据。
DOI：
10.1111/j.1471-4159.1992.tb08446.x
复制
发表时间：
1992
影响因子：
4.7
通讯作者：
Chantler,PD
中科院分区：
文献类型：
--
作者：
Li,D;Chantler,PD
Myosin I是一种基于肌动蛋白的马达，负责为变形虫和黏菌的各种运动活动提供动力，并且先前在脊椎动物中被发现作为肠上皮细胞微绒毛的侧桥。尽管神经元表现出广泛的细胞和细胞内运动，包括在发育过程中产生变形虫样生长锥，但在这些过程中负责运动的蛋白质尚不清楚。在这里，我们报道了从牛脑中分离出的部分纯化蛋白，该蛋白富含150‐kDa蛋白；免疫化学和生化分析表明，该蛋白具有许多功能特性，这些特性归因于来自不同来源的肌球蛋白I。这些特性包括升高的K+ - EDTA atp酶，适度激活的Mg2+ - atp酶，结合钙调蛋白的能力，以及与磷脂酰丝氨酸（而不是磷脂酰胆碱）制成的磷脂囊泡的现成结合。这些特性的结合，再加上150 kDa的分子质量（迄今发现的大多数肌球蛋白I分子的分子质量在110-130 kDa之间），还被抗肌球蛋白I抗体识别，表明在哺乳动物大脑中存在肌球蛋白I家族的新成员。
Myosin I is an actin‐based motor responsible for powering a wide variety of motile activities in amebae and slime molds and has been found previously in vertebrates as the lateral bridges within intestinal epithelial cell microvilli. Although neurons exhibit extensive cellular and intracellular motility, including the production of ameboid‐like growth cones during development, the proteins responsible for the motor in these processes are unknown. Here, we report the isolation of a partially purified protein fraction from bovine brain that is enriched for a 150‐kDa protein; immunochemical and biochemical analyses suggest that this protein possesses a number of functional properties that have been ascribed to myosin I from various sources. These properties include an elevated K+‐EDTA ATPase, a modestactin‐activated Mg2+‐ATPase, the ability to bind calmodulin, and a ready association with phospholipid vesicles made from phosphatidylserine, but not from phosphatidylcholine. The combination of these properties, together with a molecular mass of 150 kDa (most myosin I molecules found to date have molecular masses in the range 110–130 kDa) yet recognition by an anti‐myosin I antibody, suggests the presence of a new member of the myosin I family within mammalian brain.