Jiang Rui, Feng Qingzhou, Nong Daguan, Kang You Jung, Sept David, Hancock William O
Intercollege Program in Integrative and Biomedical Physiology, Pennsylvania State University, University Park, PA 16802.
Department of Biomedical Engineering, Pennsylvania State University, University Park, PA 16802.
bioRxiv. 2024 Oct 27:2024.10.23.619892. doi: 10.1101/2024.10.23.619892.
Intracellular vesicles are typically transported by a small number of kinesin and dynein motors. However, the slow microtubule binding rate of kinesin-1 observed in biophysical studies suggests that long-range transport may require a high number of motors. To address the discrepancy in motor requirements between and studies, we reconstituted motility of 120-nm-diameter liposomes driven by multiple GFP-labeled kinesin-1 motors. Consistent with predictions based on previous binding rate measurements, we found that long-distance transport requires a high number of kinesin-1 motors. We hypothesized that this discrepancy from observations may arise from differences in motor organization and tested whether motor clustering can enhance transport efficiency using a DNA scaffold. Clustering just three motors improved liposome travel distances across a wide range of motor numbers. Our findings demonstrate that, independent of motor number, the arrangement of motors on a vesicle regulates transport distance, suggesting that differences in motor organization may explain the disparity between and motor requirements for long-range transport.
细胞内囊泡通常由少量驱动蛋白和动力蛋白马达运输。然而,生物物理研究中观察到的驱动蛋白-1与微管的缓慢结合速率表明,长距离运输可能需要大量马达。为了解决体外研究和体内研究在马达需求上的差异,我们重构了由多个绿色荧光蛋白标记的驱动蛋白-1马达驱动的直径为120纳米的脂质体的运动性。与基于先前结合速率测量的预测一致,我们发现长距离运输需要大量的驱动蛋白-1马达。我们推测,这种与体内观察结果的差异可能源于马达组织的差异,并使用DNA支架测试了马达聚集是否可以提高运输效率。仅将三个马达聚集在一起,就能在广泛的马达数量范围内提高脂质体的移动距离。我们的研究结果表明,与马达数量无关,囊泡上马达的排列方式调节运输距离,这表明马达组织的差异可能解释了体外和体内长距离运输在马达需求上的差异。