Turnover of the actomyosin complex in zebrafish embryos directs geometric remodelling and the recruitment of lipid droplets.
Turnover of the actomyosin complex in zebrafish embryos directs geometric remodelling and the recruitment of lipid droplets.
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DOI：
10.1038/srep13915
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发表时间：
2015-09-10
影响因子：
4.6
通讯作者：
Kumar Sinha D
中科院分区：
文献类型：
--
作者：
Dutta A;Kumar Sinha D
脂滴（LDs），胆固醇和脂肪的水库，是细胞内水解脂质的细胞器。在斑马鱼胚胎中，肌动球蛋白复合物和丝状微管控制LD几何形状的周期性调节。与现有的LD运输涉及驱动蛋白-微管系统的假设相反，我们发现它们向胚盘的募集依赖于肌动球蛋白的营业额，并且独立于微管。对于第一次，我们报告存在两种不同的状态的LD，一个非活性和活性状态，周期性地发生，耦合弱的裂解周期。LD更大，更圆，在非活性状态下更稳定，其中LD的几何形状由肌动球蛋白以及微管维持。活性状态具有较小且形状不规则的LD，其显示与肌动蛋白解聚有关的形状波动。由于LD的大多数功能都采用表面相互作用，因此我们对LD几何结构及其调控的研究结果为与LD特定功能相关的机制带来了新的见解，例如它们对脂肪或蛋白质的储存能力，脂解等。
Lipid droplets (LDs), reservoirs of cholesterols and fats, are organelles that hydrolyse lipids in the cell. In zebrafish embryos, the actomyosin complex and filamentous microtubules control the periodic regulation of the LD geometry. Contrary to the existing hypothesis that LD transport involves the kinesin-microtubule system, we find that their recruitment to the blastodisc depends on the actomyosin turnover and is independent of the microtubules. For the first time we report the existence of two distinct states of LDs, an inactive and an active state, that occur periodically, coupled weakly to the cleavage cycles. LDs are bigger, more circular and more stable in the inactive state in which the geometry of the LDs is maintained by actomyosin as well as microtubules. The active state has smaller and irregularly shaped LDs that show shape fluctuations that are linked to actin depolymerization. Because most functions of LDs employ surface interactions, our findings on the LD geometry and its regulation bring new insights to the mechanisms associated with specific functions of LDs, such as their storage capacity for fats or proteins, lipolysis etc.