Lipid droplet motility and organelle contacts.
Lipid droplet motility and organelle contacts.
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DOI：
10.1177/2515256419895688
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发表时间：
2019-01-01
期刊：
影响因子：
--
通讯作者：
Welte, M A
中科院分区：
文献类型：
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作者：
Kilwein, Marcus D;Welte, M A
脂滴（LD）是能量稳态和广泛的细胞过程中不可或缺的脂肪储存细胞器。LD在物理上和功能上与许多伴侣细胞器相互作用，包括ER、线粒体、溶酶体和过氧化物酶体。最近的研究结果表明，LD细胞器间接触的动力学部分由LD细胞内运动控制。LD可以通过驱动蛋白-1、细胞质动力蛋白和V型肌球蛋白直接由马达蛋白沿着肌动蛋白丝或微管运输。LD也可以通过搭其他细胞器的便车、细胞质流动和潜在的肌动蛋白聚合来间接推进。虽然将马达连接到LD的锚仍然难以捉摸，但已经确定了LD运动的其他调节剂，范围从轨道的修饰到马达辅因子到LD蛋白的围脂蛋白家族的成员。操纵这些调节途径提供了一种工具，以探测是否改变运动影响细胞器的接触，并揭示了LD运动可以促进与许多合作伙伴的相互作用，代谢的深远影响。LD运动可以引起LD在聚集和分散状态之间的剧烈重新分布，从而导致改变的细胞器接触和LD周转。我们建议，LD运动，从而可以促进开关的细胞的代谢状态。最后，LD运动也是重要的LD分配在细胞分裂。在许多动物胚胎中，不均匀的分配导致不同子细胞中LD含量的巨大差异，表明细胞类型特异性LD需求。
Lipid droplets (LDs) are fat storage organelles integral to energy homeostasis and a wide range of cellular processes. LDs physically and functionally interact with many partner organelles, including the ER, mitochondria, lysosomes, and peroxisomes. Recent findings suggest that the dynamics of LD inter-organelle contacts is in part controlled by LD intracellular motility. LDs can be transported directly by motor proteins along either actin filaments or microtubules, via Kinesin-1, Cytoplasmic Dynein, and type V Myosins. LDs can also be propelled indirectly, by hitchhiking on other organelles, cytoplasmic flows, and potentially actin polymerization. Although the anchors that attach motors to LDs remain elusive, other regulators of LD motility have been identified, ranging from modification of the tracks to motor co-factors to members of the perilipin family of LD proteins. Manipulating these regulatory pathways provides a tool to probe whether altered motility affects organelle contacts and has revealed that LD motility can promote interactions with numerous partners, with profound consequences for metabolism. LD motility can cause dramatic redistribution of LDs between a clustered and a dispersed state, resulting in altered organelle contacts and LD turnover. We propose that LD motility can thus promote switches in the metabolic state of a cell. Finally, LD motility is also important for LD allocation during cell division. In a number of animal embryos, uneven allocation results in a large difference in LD content in distinct daughter cells, suggesting cell-type specific LD needs.