MICROTUBULE SLIDING IN FLAGELLAR AXONEMES OF CHLAMYDOMONAS-MUTANTS MISSING INNER-ARM OR OUTER-ARM DYNEIN - VELOCITY-MEASUREMENTS ON NEW TYPES OF MUTANTS BY AN IMPROVED METHOD
MICROTUBULE SLIDING IN FLAGELLAR AXONEMES OF CHLAMYDOMONAS-MUTANTS MISSING INNER-ARM OR OUTER-ARM DYNEIN - VELOCITY-MEASUREMENTS ON NEW TYPES OF MUTANTS BY AN IMPROVED METHOD
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DOI：
10.1002/cm.970190406
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发表时间：
1991-01-01
影响因子：
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通讯作者：
KAMIYA, R
中科院分区：
文献类型：
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作者：
KURIMOTO, E;KAMIYA, R
为了帮助了解内部和外部动力蛋白臂在轴丝运动的功能特性，滑动速度的外部双峰进行了测量，在解体的衣原体突变体缺乏任何一个武器的轴丝。在改进的溶液条件下的测量产生了比先前研究中观察到的滑动速度显著更高的滑动速度[Okagaki和Kamiya，1986，J. Cell Biol.103：1895-1902]。与先前的研究一样，发现野生型（wt）和缺失外臂的突变体（oda 1）的轴丝速度差异很大：在0.5 mM Mg-ATP时，wt为18.5 +/- 4.1-μ m/sec，oda 1为4.4 +/- 2.3-μ m/sec。相反，两种类型的突变体（ida 2和ida 4），缺乏不同的两套内臂重链的轴丝显示速度几乎相同的野生型速度。此外，轴丝的一个非能动的双突变体ida 2 x ida 4进行了类似的高速度滑动解体，虽然不太频繁比单突变体的轴丝。这些观察结果支持这一假设，即内部和外部动力蛋白臂在崩解的轴丝驱动微管在不同的速度，它是更快的外臂，决定了整体速度时，双臂都存在。内臂对于滑动的起始可能是重要的。因此，轴丝似乎配备了两种（或更多种）具有不同内在速度的马达。
To help understand the functional properties of inner and outer dynein arms in axonemal motility, sliding velocities of outer doublets were measured in disintegrating axonemes of Chlamydomonas mutants lacking either of the arms. Measurements under improved solution conditions yielded significantly higher sliding velocities than those observed in a previous study [Okagaki and Kamiya, 1986, J. Cell Biol. 103:1895-1902]. As in the previous study, it was found that the velocities in axonemes of wild type (wt) and a mutant (oda1) missing the outer arm differ greatly: 18.5 +/- 4.1-mu-m/sec for wt and 4.4 +/- 2.3-mu-m/sec for oda1 at 0.5 mM Mg-ATP. In contrast, axonemes of two types of mutants (ida2 and ida4) that lacked different sets of two inner-arm heavy chains displayed velocities almost identical with the wild-type velocity. Moreover, axonemes of a non-motile double mutant ida2 x ida4 underwent sliding disintegration at a similar high velocity, although less frequently than in axonemes of single mutants. These observations support the hypothesis that the inner and outer dynein arms in disintegrating axonemes drive microtubules at different speeds and it is the faster outer arm that determines the overall speed when both arms are present. The inner arm may be important for the initiation of sliding. The axoneme thus appears to be equipped with two (or more) types of motors with different intrinsic speeds.