Regulation of flagellar dynein by the axonemal central apparatus
Regulation of flagellar dynein by the axonemal central apparatus
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DOI：
10.1002/cm.10031
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发表时间：
2002-05-01
影响因子：
--
通讯作者：
Smith, EF
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文献类型：
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作者：
Smith, EF
许多研究表明，中央器，辐射辐条，和动力蛋白调节复合物形成一个信号通路，调节真核生物鞭毛中的动力蛋白活性。这种调节涉及锚定在轴丝上的几种激酶和磷酸酶的作用。为了进一步研究中央装置在这一信号通路中的作用，我们利用微管滑动试验来评估动力蛋白在中央装置缺陷型衣原体突变体中的活性。与野生型轴丝相比，从pf 18和pf 15（缺乏整个中央装置）和从pf 16（缺乏C1中央微管）分离的轴丝具有降低的微管滑动速度。基于从辐射状无辐条突变体中分离的轴丝的功能分析，我们假设酪蛋白激酶I（CK 1）和cAMP依赖性蛋白激酶（PKA）的抑制剂将拯救动力蛋白活性并增加中央无辐条突变体中的微管滑动速度。用DRB（一种CK 1抑制剂）治疗从pf 18和pf 16分离的轴突，但不使用PKI。PKA抑制剂，使动力蛋白活性恢复到野生型水平。DRB诱导的增加动力蛋白驱动的微管滑动抑制，如果轴丝首先孵育的磷酸酶抑制剂，微囊藻毒素。抑制pf-15轴丝中的CK 1。其缺乏中心对以及PP 2A [Yang等人，2000：J. Cell Sci. 113：91-102]，没有增加微管滑动速度。这些数据是一致的模型中，中央装置，特别是C1微管，调节动力蛋白通过与径向辐条，最终改变CK 1和PP 2A的活性的相互作用。这些数据也与动力蛋白臂附近轴丝CK 1和PP 2A的定位一致。(C)2002 Wiley-Liss，Inc.
Numerous studies indicate that the central apparatus, radial spokes, and dynein regulatory complex form a signaling pathway that regulates dynein activity in eukaryotic flagella. This regulation involves the action of several kinases and phosphatases anchored to the axoneme. To further investigate the role of the central apparatus in this signaling pathway, we have taken advantage of a microtubule-sliding assay to assess dynein activity in central apparatus defective mutants of Chlamydomonas. Axonemes isolated from both pf18 and pf15 (lacking the entire central apparatus) and from pf16 (lacking the C1 central microtubule) have reduced microtubule-sliding velocity compared with wild-type axonemes. Based on functional analyses of axonemes isolated from radial spokeless mutants, we hypothesized that inhibitors of casein kinase I (CK1) and cAMP dependent protein kinase (PKA) would rescue dynein activity and increase microtubule-sliding velocity in central pairless mutants. Treatment of axonernes isolated from both pf18 and pf16 with DRB, a CK1 inhibitor, but not with PKI. a PKA inhibitor, restored dynein activity to wild-type levels. The DRB-induced increase in dynein-driven microtubule sliding was inhibited if axonemes were first incubated with the phosphatase inhibitor, microcystin. Inhibiting CK1 in pf-15 axonemes. which lack the central pair as well as PP2A [Yang et al., 2000: J. Cell Sci. 113:91-102], did not increase microtubule-sliding velocity. These data are consistent with a model in which the central apparatus, and specifically the C1 microtubule, regulate dynein through interactions with the radial spokes that ultimately alter the activity of CK1 and PP2A. These data are also consistent with localization of axonemal CK1 and PP2A near the dynein arms. (C) 2002 Wiley-Liss, Inc.