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

KIF5B-mediated internalization of FMDV promotes virus infection

Foot-and-mouth disease (FMD) is a highly contagious and economically important disease, which is caused by the FMD virus (FMDV). Although the cell receptor for FMDV has been identified, the specific mechanism of FMDV internalization after infection remains unknown. In this study, we found that kinesin family member 5B (KIF5B) plays a vital role during FMDV internalization. Moreover, we confirmed the interaction between KIF5B and FMDV structural protein VP1 by co-immunoprecipitation (Co-IP) and co-localization in FMDV-infected cells. In particular, the stalk [amino acids (aa) 413-678] domain of KIF5B was indispensable for KIF5B-VP1 interaction. Moreover, overexpression of KIF5B dramatically enhanced FMDV replication; consistently, knockdown or knockout of KIF5B suppressed FMDV replication. Furthermore, we also demonstrated that KIF5B promotes the internalization of FMDV via regulating clathrin uncoating. KIF5B also promotes the transmission of viral particles to early and late endosomes during the early stages of infection. In conclusion, our results demonstrate that KIF5B promotes the internalization of FMDV via regulating clathrin uncoating and intracellular transport. This study may provide a new therapeutic target for developing FMDV antiviral drugs.

Kinesin-1 Regulates Endocytic Trafficking of Classical Swine Fever Virus along Acetylated Microtubules

Classical swine fever (CSF), caused by classical swine fever virus (CSFV), is an important and highly infectious pig disease worldwide. Kinesin-1, a molecular motor responsible for transporting cargo along the microtubule, has been demonstrated to be involved in the infections of diverse viruses. However, the role of kinesin-1 in the CSFV life cycle remains unknown. Here, we first found that Kif5B played a positive role in CSFV entry by knockdown or overexpression of Kif5B. Subsequently, we showed that Kif5B was associated with the endosomal and lysosomal trafficking of CSFV in the early stage of CSFV infection, which was reflected by the colocalization of Kif5B and Rab7, Rab11, or Lamp1. Interestingly, trichostatin A (TSA) treatment promoted CSFV proliferation, suggesting that microtubule acetylation facilitated CSFV endocytosis. The results of chemical inhibitors and RNA interference showed that Rac1 and Cdc42 induced microtubule acetylation after CSFV infection. Furthermore, confocal microscopy revealed that cooperation between Kif5B and dynein help CSFV particles move in both directions along microtubules. Collectively, our study shed light on the role of kinesin motor Kif5B in CSFV endocytic trafficking, indicating the dynein/kinesin-mediated bidirectional CSFV movement. The elucidation of this study provides the foundation for developing CSFV antiviral drugs. IMPORTANCE The minus end-directed cytoplasmic dynein and the plus end-directed kinesin-1 are the molecular motors that transport cargo on microtubules in intracellular trafficking, which plays a notable role in the life cycles of diverse viruses. Our previous studies have reported that the CSFV entry host cell is dependent on the microtubule-based motor dynein. However, little is known about the involvement of kinesin-1 in CSFV infection. Here, we revealed the critical role of kinesin-1 that regulated the viral endocytosis along acetylated microtubules induced by Cdc42 and Rac1 after CSFV entry. Mechanistically, once CSFV transported by dynein met an obstacle, it recruited kinesin-1 to move in reverse to the anchor position. This study extends the theoretical basis of intracellular transport of CSFV and provides a potential target for the control and treatment of CSFV infection.

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

Many neurodegenerative diseases, such as Alzheimer's disease (AD) and frontotemporal dementia with Parkinsonism linked to chromosome 17, are characterized by tau pathology. Numerous motor proteins, many of which are involved in synaptic transmission, mediate transport in neurons. Dysfunction in motor protein-mediated neuronal transport mechanisms occurs in several neurodegenerative disorders but remains understudied in AD. Kinesins are the most important molecular motor proteins required for microtubule-dependent transport in neurons, and kinesin-1 is crucial for neuronal transport among all kinesins. Although kinesin-1 is required for normal neuronal functions, the dysfunction of these motor domains leading to neurodegenerative diseases is not fully understood. Here, we reported that the kinesin-I heavy chain (KIF5B), a key molecular motor protein, is involved in tau homeostasis in AD cells and animal models. We found that the levels of KIF5B in P301S tau mice are high. We also found that the knockdown and knockout (KO) of KIFf5B significantly decreased the tau stability, and overexpression of KIF5B in KIF5B-KO cells significantly increased the expression of phosphorylated and total tau levels. This suggested that KIF5B might prevent tau accumulation. By conducting experiments on P301S tau mice, we showed that partially reducing KIF5B levels can reduce hyperphosphorylation of the human tau protein, formation of insoluble aggregates, and memory impairment. Collectively, our results suggested that decreasing KIF5B levels is sufficient to prevent and/or slow down abnormal tau behavior of AD and other tauopathies.

Understanding how kinesin motor proteins regulate postsynaptic function in neuron

The Kinesin superfamily proteins (KIFs) are major molecular motors that transport diverse set of cargoes along microtubules to both the axon and dendrite of a neuron. Much of our knowledge about kinesin function is obtained from studies on axonal transport. Emerging evidence reveals how specific kinesin motor proteins carry cargoes to dendrites, including proteins, mRNAs and organelles that are crucial for synapse development and plasticity. In this review, we will summarize the major kinesin motors and their associated cargoes that have been characterized to regulate postsynaptic function in neuron. We will also discuss how specific kinesins are selectively involved in the development of excitatory and inhibitory postsynaptic compartments, their regulation by post-translational modifications (PTM), as well as their roles beyond conventional transport carrier.