Kettin, a major source of myofibrillar stiffness in Drosophila indirect flight muscle.
Kettin, a major source of myofibrillar stiffness in Drosophila indirect flight muscle.
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DOI：
10.1083/jcb.200104016
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发表时间：
2001-09-03
期刊：
影响因子：
--
通讯作者：
Linke WA
中科院分区：
文献类型：
--
作者：
Kulke M;Neagoe C;Kolmerer B;Minajeva A;Hinssen H;Bullard B;Linke WA
Kettin是昆虫肌肉中的一种高分子量蛋白，在肌节中与肌动蛋白和α-辅肌动蛋白结合。为了研究kettin的功能作用，我们将免疫标记实验与果蝇间接飞行肌（IFM）肌原纤维的机械和生物化学研究相结合。用kettin抗体标记的拉伸IFM肌节的显微照片显示Z盘外周染色。提取酮蛋白相关肌动蛋白后，还对A带边缘进行染色。与此相反，染色模式的projectin，另一个IFM-I带蛋白，没有改变肌动蛋白去除。对单个IFM肌原纤维进行力测量以建立被动长度-张力关系并记录被动刚度。在凝溶胶蛋白孵育期间，硬度在几秒钟内降低，并且在用μ-钙蛋白酶消化kettin后降低至相似程度。免疫印迹表明kettin亚型在正常果蝇IFM肌原纤维和肌动蛋白无效突变体的肌原纤维中的存在。斑点杂交分析表明，COOH-末端kettin结构域的肌球蛋白的结合。我们的结论是，kettin不仅连接到肌动蛋白，但也到粗丝的末端。Kettin沿着projectin可能构成昆虫IFM的弹性纤维系统，并决定了肌肉的高刚度所必需的拉伸激活。这两种蛋白质可能通过表达不同大小的亚型来调节肌原纤维硬度。
Kettin is a high molecular mass protein of insect muscle that in the sarcomeres binds to actin and α-actinin. To investigate kettin's functional role, we combined immunolabeling experiments with mechanical and biochemical studies on indirect flight muscle (IFM) myofibrils of Drosophila melanogaster. Micrographs of stretched IFM sarcomeres labeled with kettin antibodies revealed staining of the Z-disc periphery. After extraction of the kettin-associated actin, the A-band edges were also stained. In contrast, the staining pattern of projectin, another IFM–I-band protein, was not altered by actin removal. Force measurements were performed on single IFM myofibrils to establish the passive length-tension relationship and record passive stiffness. Stiffness decreased within seconds during gelsolin incubation and to a similar degree upon kettin digestion with μ-calpain. Immunoblotting demonstrated the presence of kettin isoforms in normal Drosophila IFM myofibrils and in myofibrils from an actin-null mutant. Dotblot analysis revealed binding of COOH-terminal kettin domains to myosin. We conclude that kettin is attached not only to actin but also to the end of the thick filament. Kettin along with projectin may constitute the elastic filament system of insect IFM and determine the muscle's high stiffness necessary for stretch activation. Possibly, the two proteins modulate myofibrillar stiffness by expressing different size isoforms.
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影响因子：
11.4
作者：
LAKEY, A;LABEIT, S;BULLARD, B
通讯作者：
BULLARD, B
影响因子：
56.9
作者：
LABEIT, S;KOLMERER, B
通讯作者：
KOLMERER, B
影响因子：
5.6
作者：
BULLARD, B;LEONARD, K;FYRBERG, E
通讯作者：
FYRBERG, E
影响因子：
5.6
作者：
BULLARD, B;HAMMOND, KS;LUKE, BM
通讯作者：
LUKE, BM
DOI：
10.1073/pnas.95.14.8052
发表时间：
1998-07-07
影响因子：
11.1
作者：
Linke, WA;Ivemeyer, M;Kolmerer, B
通讯作者：
Kolmerer, B