Guha S, Mitra MK, Pagonabarraga I, Muhuri S. Novel mechanism for oscillations in catchbonded motor-filament complexes.
Biophys J 2021;
120:4129-4136. [PMID:
34329628 DOI:
10.1016/j.bpj.2021.07.018]
[Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2020] [Revised: 04/11/2021] [Accepted: 07/19/2021] [Indexed: 11/26/2022] Open
Abstract
Generation of mechanical oscillations is ubiquitous to a wide variety of intracellular processes ranging from activity of muscle fibres to oscillations of the mitotic spindle. The activity of motors plays a vital role in maintaining the integrity of the mitotic spindle structure and in generating spontaneous oscillations. While the structural features and properties of the individual motors are well characterized, their implications on the functional behaviour of motor-filament complexes is more involved. We show that force-induced allosteric deformations in dynein, which results in catchbonding behaviour, 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 behaviour and oscillations in motor-filament complexes, such as mitotic spindles.
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