LeDizet M, Piperno G
Department of Cell Biology and Anatomy, Mount Sinai School of Medicine, New York, New York 10029, USA.
Mol Biol Cell. 1995 Jun;6(6):697-711. doi: 10.1091/mbc.6.6.697.
We show here that I2 and I3 inner dynein arm heavy chains of Chlamydomonas axonemes are resolved into two classes: one class associated with the protein p28 and the other associated with the protein caltractin/centrin. We have determined the nucleotide sequence of the gene encoding p28, a light chain that, together with actin and caltractin/centrin, is associated with inner dynein arms I2 and I3 of Chlamydomonas axonemes. p28 is a novel protein with affinity for a subset of the inner dynein arm heavy chains, but with no apparent significant homologies to tubulin- or actin-binding proteins. An antiserum specific for p28 showed that p28 is present along the entire axoneme. The same antiserum coimmunoprecipitated p28, actin, and dynein heavy chains 2' and 2. In contrast, an anti-caltractin/centrin antiserum coimmunoprecipitated caltractin/centrin, actin, and the heavy chains 2, 3, and 3'. It is likely that the dynein heavy chain 2 associated with p28, referred to as 2A, is a different polypeptide from dynein heavy chain 2 bound to caltractin/centrin, referred to as 2B. The complex formed by heavy chain 2B, actin, and caltractin/centrin is preferentially extracted by exposure to Nonidet P-40 and is missing in mutants lacking components 1 and 2 of the dynein regulatory complex.
我们在此表明，衣藻轴丝的I2和I3内动力蛋白臂重链可分为两类：一类与蛋白质p28相关，另一类与蛋白质钙牵蛋白/中心蛋白相关。我们已经确定了编码p28的基因的核苷酸序列，p28是一种轻链蛋白，它与肌动蛋白以及钙牵蛋白/中心蛋白一起，与衣藻轴丝的I2和I3内动力蛋白臂相关。p28是一种新型蛋白质，对一部分内动力蛋白臂重链具有亲和力，但与微管蛋白或肌动蛋白结合蛋白没有明显的显著同源性。一种对p28特异的抗血清显示，p28存在于整个轴丝中。同一种抗血清共免疫沉淀了p28、肌动蛋白以及动力蛋白重链2'和2。相比之下，一种抗钙牵蛋白/中心蛋白抗血清共免疫沉淀了钙牵蛋白/中心蛋白、肌动蛋白以及重链2、3和3'。与p28相关的动力蛋白重链2（称为2A）可能是一种与结合钙牵蛋白/中心蛋白的动力蛋白重链2（称为2B）不同的多肽。由重链2B、肌动蛋白和钙牵蛋白/中心蛋白形成的复合物在暴露于诺乃洗涤剂P - 40时优先被提取，并且在缺乏动力蛋白调节复合物成分1和2的突变体中缺失。
