title: Bidirectional helical motility of cytoplasmic dynein around microtubules.
abstract: Cytoplasmic dynein is a molecular motor responsible for minus-end-directed cargo transport along microtubules (MTs). Dynein motility has previously been studied on surface-immobilized MTs in vitro, which constrains the motors to move in two dimensions. In this study, we explored dynein motility in three dimensions using an MT bridge assay. We found that dynein moves in a helical trajectory around the MT, demonstrating that it generates torque during cargo transport. Unlike other cytoskeletal motors that produce torque in a specific direction, dynein generates torque in either direction, resulting in bidirectional helical motility. Dynein has a net preference to move along a right-handed helical path, suggesting that the heads tend to bind to the closest tubulin binding site in the forward direction when taking sideways steps. This bidirectional helical motility may allow dynein to avoid roadblocks in dense cytoplasmic environments during cargo transport.
authors: Department of Physics, University of California, Berkeley, Berkeley, United States.
authors: Sinan
authors: S
authors: Can
authors: Biophysics Graduate Group, University of California, Berkeley, Berkeley, United States.
authors: Mark A
authors: MA
authors: Dewitt
authors: Department of Physics, University of California, Berkeley, Berkeley, United States Biophysics Graduate Group, University of California, Berkeley, Berkeley, United States yildiz@berkeley.edu.
authors: Ahmet
authors: A
authors: Yildiz
mesh_terms: D001692:Biological Transport; D003593:Cytoplasm / Q000737:chemistry / Q000378:metabolism; D004398:Dyneins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D005456:Fluorescent Dyes; D015870:Gene Expression; D016547:Kinesins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D008870:Microtubules / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D008954:Models, Biological; D009038:Motion; D012441:Saccharomyces cerevisiae / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D014404:Tubulin / Q000737:chemistry / Q000235:genetics / Q000378:metabolism
chemical_list: D005456:Fluorescent Dyes; D029701:Saccharomyces cerevisiae Proteins; D014404:Tubulin; C000596030:DYN1 protein, S cerevisiae; D004398:Dyneins; D016547:Kinesins
keywords: dynein; intracellular cargo transport; molecular motors; optical trap; single molecule biophysics