Myosin Va movements in normal and dilute-lethal axons provide support for a dual filament motor complex.
Myosin Va movements in normal and dilute-lethal axons provide support for a dual filament motor complex.
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DOI：
10.1083/jcb.146.5.1045
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发表时间：
1999-09-06
期刊：
影响因子：
--
通讯作者：
Bridgman PC
中科院分区：
文献类型：
--
作者：
Bridgman PC
为了研究肌球蛋白Va在细胞器轴突运输中的作用，使用显微注射的肌球蛋白Va的荧光标记抗体或表达的绿色荧光蛋白-肌球蛋白Va尾结构在活神经元中监测肌球蛋白Va相关的细胞器运动。肌球蛋白Va相关的细胞器在正常和稀释致死（肌球蛋白Va空）神经突中快速双向运动。在正常神经元中，诺考达唑使微管解聚减慢，但不能使运动停止。相反，在稀释致死神经元微管解聚停止运动。肌球蛋白Va或突触囊泡蛋白2（SV 2），其中部分共定位与肌球蛋白Va的细胞器，没有积累在稀释致死的神经元细胞体，因为与细胞器运输的顺行性偏见。然而，SV 2显示在富含酪氨酸化微管蛋白的稀释致死神经元的轴突区域中的外周积累。这表明肌球蛋白Va相关的细胞器在富含动态微管末端的区域搁浅。与这些观察结果一致，在稀释致死小鼠小脑颗粒细胞的突触前末梢表现出增加的横截面积，并有更多的突触和更大的SV 2阳性囊泡。总之，这些结果表明，肌球蛋白Va结合到细胞器，这些细胞器在轴突中沿沿着微管运输。这是一致的肌动蛋白和微管为基础的电机存在于这些细胞器。虽然肌球蛋白V活性对于轴突中的长距离运输不是必需的，但肌球蛋白Va活性对于区域中的细胞器的局部运动或加工是必需的，例如缺乏微管的突触前末梢。
To investigate the role that myosin Va plays in axonal transport of organelles, myosin Va–associated organelle movements were monitored in living neurons using microinjected fluorescently labeled antibodies to myosin Va or expression of a green fluorescent protein–myosin Va tail construct. Myosin Va–associated organelles made rapid bi-directional movements in both normal and dilute-lethal (myosin Va null) neurites. In normal neurons, depolymerization of microtubules by nocodazole slowed, but did not stop movement. In contrast, depolymerization of microtubules in dilute-lethal neurons stopped movement. Myosin Va or synaptic vesicle protein 2 (SV2), which partially colocalizes with myosin Va on organelles, did not accumulate in dilute-lethal neuronal cell bodies because of an anterograde bias associated with organelle transport. However, SV2 showed peripheral accumulations in axon regions of dilute-lethal neurons rich in tyrosinated tubulin. This suggests that myosin Va–associated organelles become stranded in regions rich in dynamic microtubule endings. Consistent with these observations, presynaptic terminals of cerebellar granule cells in dilute-lethal mice showed increased cross-sectional area, and had greater numbers of both synaptic and larger SV2 positive vesicles. Together, these results indicate that myosin Va binds to organelles that are transported in axons along microtubules. This is consistent with both actin- and microtubule-based motors being present on these organelles. Although myosin V activity is not necessary for long-range transport in axons, myosin Va activity is necessary for local movement or processing of organelles in regions, such as presynaptic terminals that lack microtubules.
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DOI：
10.1083/jcb.137.7.1589
发表时间：
1997-06-30
期刊：
The Journal of cell biology
影响因子：
--
作者：
Prekeris R;Terrian DM
通讯作者：
Terrian DM
影响因子：
5.7
作者：
Hirokawa, Nobutaka
通讯作者：
Hirokawa, Nobutaka
DOI：
10.1083/jcb.105.5.2167
发表时间：
1987-11
期刊：
The Journal of cell biology
影响因子：
--
作者：
Schulze E;Asai DJ;Bulinski JC;Kirschner M
通讯作者：
Kirschner M
影响因子：
64.5
作者：
CHENEY, RE;OSHEA, MK;MOOSEKER, MS
通讯作者：
MOOSEKER, MS
影响因子：
2.5
作者：
LUBKE, J
通讯作者：
LUBKE, J