Department of Physics, Indian Institute of Technology Bombay, Mumbai, India; Department of Physics, Savitribai Phule Pune University, Pune, India.
Department of Physics, Indian Institute of Technology Bombay, Mumbai, India.
Biophys J. 2021 Sep 21;120(18):4129-4136. doi: 10.1016/j.bpj.2021.07.018. Epub 2021 Jul 27.
Generation of mechanical oscillations is ubiquitous to a wide variety of intracellular processes, ranging from activity of muscle fibers to oscillations of the mitotic spindle. The activity of motors plays a vital role in maintaining the integrity of the mitotic spindle structure and generating spontaneous oscillations. Although the structural features and properties of the individual motors are well characterized, their implications on the functional behavior of motor-filament complexes are more involved. We show that force-induced allosteric deformations in dynein, which result in catchbonding behavior, provide a generic mechanism to generate spontaneous oscillations in motor-cytoskeletal filament complexes. The resultant phase diagram of such motor-filament systems-characterized by force-induced allosteric deformations-exhibits bistability and sustained limit-cycle oscillations in biologically relevant regimes, such as for catchbonded dynein. The results reported here elucidate the central role of this mechanism in fashioning a distinctive stability behavior and oscillations in motor-filament complexes such as mitotic spindles.
机械振荡的产生在各种细胞内过程中普遍存在，从肌肉纤维的活动到有丝分裂纺锤体的振荡。马达的活动在维持有丝分裂纺锤体结构的完整性和产生自发振荡方面起着至关重要的作用。尽管单个马达的结构特征和性质已经得到很好的描述，但它们对马达-纤维复合物的功能行为的影响更为复杂。我们表明，动力蛋白中力诱导的变构变形导致结合键行为，为马达-细胞骨架纤维复合物中自发振荡的产生提供了一种通用机制。这种马达-纤维系统的相图——由力诱导的变构变形来表征——在生物相关的范围内表现出双稳性和持续的限幅循环振荡，例如结合键的动力蛋白。这里报道的结果阐明了这种机制在塑造独特的稳定性行为和有丝分裂纺锤体等马达-纤维复合物中的振荡中的核心作用。
