Kinesin-1 and dynein use distinct mechanisms to bypass obstacles

Abstract

Kinesin-1 and cytoplasmic dynein are microtubule (MT) motors that transport intracellular cargos. It remains unclear how these motors move along MTs densely coated with obstacles of various sizes in the cytoplasm. Here, we tested the ability of single and multiple motors to bypass synthetic obstacles on MTs in vitro. Contrary to previous reports, we found that mammalian dynein is highly capable of bypassing obstacles. Unlike dynein, single kinesin motors stall in the presence of obstacles, consistent with their inability to take sideways steps to neighboring protofilaments. Kinesins overcome this limitation when working in teams, bypassing obstacles as effectively as multiple dyneins. Cargos driven by multiple kinesin or dyneins are also capable of rotating around the MT to bypass large obstacles. These results suggest that multiplicity of motors is required not only for transporting cargos over long distances and generating higher forces, but also for maneuvering of the cargos on obstacle-coated MT surfaces.

Stable tug-of-war between kinesin-1 and cytoplasmic dynein upon different ATP and roadblock concentrations

“…S3a). Our findings from the several-protofilament simulations agree with findings of Ferro et al (2019) for cargo transport. However, not allowing dynein to take side steps in the multiple protofilament simulation, dynein is again more affected than kinesin.…”

Compartmentalization of telomeres through DNA-scaffolded phase separation

“…Constructs for expressing individual components of the human shelterin complex were tagged with an N-terminal ZZ affinity tag, TEV cleavage site, and YBBR labeling site and cloned into a Baculovirus vector. A construct expressing both TPP1 and TIN2 (TIN2 did not express on its own or without a solubility tag) and constructs expressing four-or five-component shelterin were cloned using a BigBac vector as described (Ferro et al, 2019). For the four-component shelterin BigBac construct, POT1 was given an N-terminal YBBR tag, POT1 and TRF2 were each given an N-terminal ZZ affinity tag and a TEV cleavage site, and TIN2 and TPP1 were each given an N-terminal His-MBP affinity tag and a TEV cleavage site.…”

“…For a full list of constructed plasmids, see the key resources table. Protein was purified from insect cells as previously described (Ferro et al, 2019)…”

Axonal transport during injury on a theoretical axon

“…In our studies with DyNAMO, we note that the rate of influx of motors has interestingly different impacts on kinesin types. We also anticipate the use of DyNAMO in the analysis of additional neuronal kinesins (Hirokawa and Takemura, 2005;Hirokawa et al, 2009) or evaluating the impact of multiple kinesins on processivity and obstacle avoidance (Ferro et al, 2019). DyNAMO reveals how axonal MT organization and multiple kinesins interplay to generate localized axonal crowding and patterning.…”