A new role of anterograde motor Kif5b in facilitating large clathrin-coated vesicle mediated endocytosis via regulating clathrin uncoating

Abstract

Kif5b-driven anterograde transport and clathrin-mediated endocytosis (CME) are responsible for opposite intracellular trafficking, contributing to plasma membrane homeostasis. However, whether and how the two trafficking processes coordinate remain unclear. Here, we show that Kif5b directly interacts with clathrin heavy chain (CHC) at a region close to that for uncoating catalyst (Hsc70) and preferentially localizes on relatively large clathrin-coated vesicles (CCVs). Uncoating in vitro is decreased for CCVs from the cortex of kif5b conditional knockout (mutant) mouse and facilitated by adding Kif5b fragments containing CHC-binding site, while cell peripheral distribution of CHC or Hsc70 keeps unaffected by Kif5b depletion. Furthermore, cellular entry of vesicular stomatitis virus that internalizes into large CCV is inhibited by Kif5b depletion or introducing a dominant-negative Kif5b fragment. These findings showed a new role of Kif5b in regulating large CCV-mediated CME via affecting CCV uncoating, indicating Kif5b as a molecular knot connecting anterograde transport to CME.

Reduction of kinesin I heavy chain decreases tau hyperphosphorylation, aggregation, and memory impairment in Alzheimer’s disease and tauopathy models

“…All mice were housed in a specific pathogen-free facility at LAU, HKU, under a 12 h/12 h light/dark cycle, and provided with food and water. The heterozygous KIF5B knockout (KIF5B +/− ) mouse line was generated by Prof. Huang’s group ( Ni et al, 2018 ; Lin et al, 2019 ). The KIF5B +/− mice were crossed with P301S mice to obtain the experimental cohort of P301S +/− and P301S +/− ,KIF5B +/− in C57B6 background The genotype of all animals was confirmed by polymerase chain reaction (PCR).…”

Motors on track:

“…Furthermore, we found that CHC could also directly bind, albeit weakly, to kinesin-1 via its tail domain (KIF5B aa 808-963) (Figure 1F). This interaction was also reported in a recent study describing a role of direct binding by the kinesin-1 KIF5B in the uncoating of clathrin-coated vesicles (Ni et al, 2018). Altogether, we have identified clathrin as a novel MAP7D2-specific interaction partner and showed that these proteins can form a triple complex together with kinesin-1.…”

“…Here, we show that MAP7D2 has the unique property of binding and recruiting clathrin to MTs and that this MAP is important for the localization of clathrin in the axon. Kinesin-1 can also bind clathrin directly (Ni et al, 2018); we therefore hypothesize that MAP7D2 has a dual role in steering kinesin-1 transport and loading cargo onto the motor. Future experiments may resolve how large cytosolic protein complexes such as clathrin and neurofilaments are sorted and transported, and how specific MAPs can contribute to this process in a spatially regulated manner.…”

Astrocyte-to-neuron transportation of enhanced green fluorescent protein in cerebral cortex requires F-actin dependent tunneling nanotubes

“…To confirm whether EGFP was transferred from astrocytes to neurons via exosomes, we inject GW4869 in the same site injected with AAV- GFAP -Cre-EGFP and examine the dissemination of EGFP. Previous studies demonstrated that 10–20 μM GW4869 could decrease more than 70% exosomes released from neurons 28 and astrocytes 29 . Here we injected 1 μl of 80 μM GW4869 in the cortex to inhibit exosome formation thoroughly.…”