A COFILIN-LIKE PROTEIN IS INVOLVED IN THE REGULATION OF ACTIN ASSEMBLY IN DEVELOPING SKELETAL-MUSCLE
A COFILIN-LIKE PROTEIN IS INVOLVED IN THE REGULATION OF ACTIN ASSEMBLY IN DEVELOPING SKELETAL-MUSCLE
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DOI：
10.1093/oxfordjournals.jbchem.a122919
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发表时间：
1989-10-01
影响因子：
2.7
通讯作者：
OBINATA, T
中科院分区：
文献类型：
--
作者：
ABE, H;OHSHIMA, S;OBINATA, T
从鸡胚骨骼肌肌浆中分离纯化出一种分子量为20 kDa的肌动蛋白结合蛋白（简称20 K蛋白）。该蛋白质的性质与在猪脑中发现的cofilin非常相似（Nishida等（1984）Biochemistry，23，5307-5313）：它与G-和F-肌动蛋白结合，以pH依赖性方式抑制肌动蛋白聚合，抑制原肌球蛋白与F-肌动蛋白的结合，并且具有与cofilin几乎相同的分子大小和pI。制备了20 K蛋白特异性单克隆抗体（MAB-22），以检测20 K蛋白在骨骼肌发育过程中的表达和定位。用免疫印迹结合SDS-PAGE的方法对鸡胚和出壳后骨骼肌的全蛋白裂解液进行检测，发现20 K蛋白在鸡胚和出壳后骨骼肌的各个发育阶段均有表达。20 K蛋白在细胞中的位置在胚胎和成人组织之间不同;用MAB-22对胚胎肌肉冷冻切片进行免疫荧光染色，可见不规则的点状结构，但成人肌肉切片染色微弱且均匀。20 K蛋白是作为一个复杂的肌动蛋白在胚胎肌肉中，作为判断的能力，结合到DNA酶I亲和柱，而相同的蛋白质是免费的肌动蛋白在成人肌肉的细胞质。从这些结果，这表明，20 K蛋白调节肌动蛋白组装瞬时在发育中的骨骼肌。
An actin-binding protein of 20 kDa (called 20K protein) was purified from the sarcoplasmic fraction of embryonic chicken skeletal muscle. The properties of this protein were very similar to cofilin, which was discovered in porcine brain (Nishida et al. (1984) Biochemistry, 23, 5307-5313): it bound to both G- and F-actin, inhibited actin polymerization in a pH-dependent manner, inhibited binding of tropomyosin to F-actin, and had almost the same molecular size and pI as cofilin. A specific monoclonal antibody to 20K protein (MAB-22) was prepared to examine the expression and location of 20K protein during skeletal muscle development. When the whole protein lysates of embryonic and post-hatched chicken skeletal muscles were examined by means of immunoblotting combined with SDS-PAGE, 20K protein was detected in skeletal muscle through the developmental stages. Location of 20K protein in the cells differed between the embryonic and adult tissues; immunofluorescence staining of the cryosections of embryonic muscle with MAB-22 visualized irregular dot-like structures, but adult muscle sections were stained faintly and uniformly. 20K protein was present as a complex with actin in embryonic muscle, as judged by the ability to bind to a DNase I affinity column, while the same protein was free from actin in the cytoplasm of adult muscle. From these results, it is suggested that 20K protein regulates actin assembly transiently in developing skeletal muscle.