• BMB Reports
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• v.56 no.3
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• pp.178-183
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• 2023

Huntington's disease (HD) is a neurodegenerative disorder, of which pathogenesis is caused by a polyglutamine expansion in the amino-terminus of huntingtin gene that resulted in the aggregation of mutant HTT proteins. HD is characterized by progressive motor dysfunction, cognitive impairment and neuropsychiatric disturbances. Histone deacetylase 6 (HDAC6), a microtubule-associated deacetylase, has been shown to induce transport- and release-defect phenotypes in HD models, whilst treatment with HDAC6 inhibitors ameliorates the phenotypic effects of HD by increasing the levels of α-tubulin acetylation, as well as decreasing the accumulation of mutant huntingtin (mHTT) aggregates, suggesting HDAC6 inhibitor as a HD therapeutics. In this study, we employed in vitro neural stem cell (NSC) model and in vivo YAC128 transgenic (TG) mouse model of HD to test the effect of a novel HDAC6 selective inhibitor, CKD-504, developed by Chong Kun Dang (CKD Pharmaceutical Corp., Korea). We found that treatment of CKD-504 increased tubulin acetylation, microtubule stabilization, axonal transport, and the decrease of mutant huntingtin protein in vitro. From in vivo study, we observed CKD-504 improved the pathology of Huntington's disease: alleviated behavioral deficits, increased axonal transport and number of neurons, restored synaptic function in corticostriatal (CS) circuit, reduced mHTT accumulation, inflammation and tau hyperphosphorylation in YAC128 TG mouse model. These novel results highlight CKD-504 as a potential therapeutic strategy in HD.

• Journal of Life Science
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• v.33 no.7
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• pp.531-537
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• 2023

Intracellular and axonal transport is mediated by microtubule-dependent motor proteins, such as kinesins and cytoplasmic dynein. Kinesin moves along the microtubule to the positive end of the microtubule, while dynein moves to the negative end of the microtubule. Kinesin-1 was first identified as a kinesin superfamily protein (KIF) that functions in the intracellular transport of various cargoes, including organelles, neurotransmitter receptors, and mRNA-protein complexes, through interactions between the carboxyl (C)-terminal domain and the cargo. It interacts with other cargoes, but the adapter/scaffold proteins that mediate between kinesin-1 and the cargo have yet to be fully identified. In this study, a yeast two-hybrid screen was used to identify adapter proteins that interact with the C-terminal region of KIF5A. We found an association between the C-terminal region of KIF5A and the cyclin-dependent kinase 2-associated protein 1 (CDK2AP1), originally identified in malignant hamster oral keratinocytes. CDK2AP1 bound to the C-terminal region of KIF5A and did not interact with KIF3A (the motor of kinesin-2), KIF5B, KIF5C, and kinesin light chain 1 (KLC1). The C-terminal region of CDK2AP1 is essential for its interaction with KIF5A. When co-expressed in HEK-293T cells, CDK2AP1 and kinesin-1 co-immunoprecipitated and co-localized in the cells. These results suggest that the KIF5A-CDK2AP1 interaction serves as an adapter protein connecting kinesin-1 and the cargo when kinesin-1 transports cargo in cells.

• Journal of Life Science
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• v.23 no.8
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• pp.978-983
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• 2013

Kinesin-II, a molecular motor, consists of two different motor subunits, KIF3A and KIF3B, and one large kinesin superfamily-associated protein 3 (KAP3), forming a heterotrimeric complex. KAP3 is associated with the tail domains of motor subunits. However, its exact role remains unclear. Here, we demonstrated KAP3 binding to the carboxyl (C)-terminal tail region of HS-associated protein X-1 (HAX-1). HAX-1 bound to the C-terminal region of KAP3, but not to KIFs (KIF3A, KIF3B, and KIF5B) and the kinesin light chain (KLC) in the yeast two-hybrid assays. The interaction was further confirmed in the glutathione S-transferase (GST) pull-down assay and by co-immunoprecipitation. Anti- HAX-1 antibody as well as anti-KIF3A antibody co-immunoprecipitated KIF3B and KAP3 from mouse brain extracts. These results suggest that KAP3 could mediate the interaction between Kinesin-II and HAX-1.

• Journal of Life Science
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• v.27 no.10
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• pp.1191-1198
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• 2017

Vesicles and organelles are transported along microtubule and delivered to appropriate compartments in cells. The intracellular transport process is mediated by molecular motor proteins, kinesin, and dynein. Kinesin is a plus-end-directed molecular motor protein that moves the various cargoes along microtubule tracks. Kinesin 1 is first isolated from squid axoplasm is a dimer of two heavy chains (KHCs, also called KIF5s), each of which is associated with the light chain (KLC). KIF5s interact with many different binding proteins through their carboxyl (C)-terminal tail region, but their binding proteins have yet to be specified. To identify the interacting proteins for KIF5A, we performed the yeast two-hybrid screening and found a specific interaction with Ras-GTPase-activating protein (GAP) Src homology3 (SH3)-domain-binding protein 2 (G3BP2), which is involved in stress granule formation and mRNA-protein (mRNP) localization. G3BP2 bound to the C-terminal 73 amino acids of KIF5A but did not interact with the KIF5B, nor the KIF5C in the yeast two-hybrid assay. The arginine-glycine-glycine (RGG)/Gly-rich region domain of G3BP2 is a minimal binding domain for interaction with KIF5A. However, G3BP1 did not interact with KIF5A. When co-expressed in HEK-293T cells, G3BP2 co-localized with KIF5A and was co-immunoprecipitated with KIF5A. These results indicate that G3BP2, which was originally identified as a Ras-GAP SH3 domain-binding protein, is a protein that interacts with KIF5A.

• BMB Reports
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• v.45 no.8
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• pp.427-432
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• 2012

Primary cilia, single hair-like appendage on the surface of the most mammalian cells, were once considered to be vestigial cellular organelles for a past century because of their tiny structure and unknown function. Although they lack ancestral motility function of cilia or flagella, they share common ground with multiciliated motile cilia and flagella on internal structure such as microtubule based nine outer doublets nucleated from the base of mother centrioles called basal body. Making cilia, ciliogenesis, in cells depends on the cell cycle stage due to reuse of centrioles for cell division forming mitotic spindle pole (M phase) and assembling cilia from basal body (starting G1 phase and maintaining most of interphase). Ciliary assembly required two conflicting processes such as assembly and disassembly and balance between these two processes determines the length of cilia. Both process required highly conserved transport system to supply needed substance to grow tip of cilia and bring ciliary turnover product back to the base of cilia using motor protein, kinesin and dynein, and transport protein complex, IFT particles. Disruption of ciliary structure or function causes multiple human disorder called ciliopathies affecting disease of diverse ciliated tissues ranging from eye, kidney, respiratory tract and brain. Recent explosion of research on the primary cilia and their involvement on animal development and disease attracts scientific interest on how extensively the function of cilia related to specific cell physiology and signaling pathway. In this review, I introduce general features of primary cilia and recent progress in understanding of the ciliary length control and signaling pathways transduced through primary cilia in vertebrates.

• Parasites, Hosts and Diseases
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• v.60 no.3
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• pp.163-172
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• 2022

Kinesin-13 (Kin-13), a depolymerizer of microtubule (MT), has been known to affect the length of Giardia. Giardia Kin-13 (GlKin-13) was localized to axoneme, flagellar tips, and centrosomes, where phosphorylated forms of Giardia polo-like kinase (GlPLK) were distributed. We observed the interaction between GlKin-13 and GlPLK via co-immunoprecipitation using transgenic Giardia cells expressing Myc-tagged GlKin-13, hemagglutinin-tagged GlPLK, and in vitro-synthesized GlKin-13 and GlPLK proteins. In vitro-synthesized GlPLK was demonstrated to auto-phosphorylate and phosphorylate GlKin-13 upon incubation with [γ-³²P]ATP. Morpholino-mediated depletion of both GlKin-13 and GlPLK caused an extension of flagella and a decreased volume of median bodies in Giardia trophozoites. Our results suggest that GlPLK plays a pertinent role in formation of flagella and median bodies by modulating MT depolymerizing activity of GlKin-13.

• The Korean Journal of Physiology and Pharmacology
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• v.8 no.3
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• pp.167-172
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• 2004

The kinesin proteins (KIFs) make up a large superfamily of molecular motors that transport cargo such as vesicles, protein complexes, and organelles. KIF5 is a heterotetrameric motor that conveys vesicles and plays an important role in neuronal function. Here, we used the yeast two-hybrid system to identify the neuronal protein(s) that interacts with the tail region of KIF5 and found a specific interaction with ${\beta}III$ spectrin. The amino acid residues between 1394 and 1774 of ${\beta}III$ spectrin were required for the interaction with KIF5C. ${\beta}III$ spectrin also bound to the tail region of neuronal KIF5A and ubiquitous KIF5B but not to other kinesin family members in the yeast two-hybrid assay. In addition, these proteins showed specific interactions, confirmed by GST pull-down assay and co-immunoprecipitation. ${\beta}III$ spectrin interacted with GST-KIF5 fusion proteins, but not with GST alone. An antibody to ${\beta}III$ spectrin specifically co-immunoprecipitated KIF5s associated with ${\beta}III$ spectrin from mouse brain extracts. These results suggest that KTF5 motor proteins transport vesicles or organelles that are coated with ${\beta}III$ spectrin.

• Journal of Life Science
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• v.26 no.6
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• pp.698-704
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• 2016

The intracellular transport of organelles and protein complexes is mediated by kinesin superfamily proteins (KIFs). The first kinesin, kinesin 1, was identified as a molecular motor protein that moves various organelles and protein complexes along the microtubule rails in cells. Kinesin 1 is a tetramer of two heavy chains (KHCs, also called KIF5s) and two kinesin light chains (KLCs). KIF5s interact with many different proteins through their tail region, but their binding proteins have not yet been fully identified. To identify the interaction proteins for KIF5A, we performed yeast two-hybrid screening and found a specific interaction with ferritin heavy chain (Frt-h), which has a role in iron storage and detoxification. Frt-h bound to the amino acid residues between 800 and 940 of KIF5A and to other KIF5s in the yeast two-hybrid assay. The coiled-coil domain of Frt-h is essential for interaction with KIF5A. In addition, ferritin light chain (Frt-l) interacted with KIF5s in the yeast two-hybrid assay. In addition, these proteins showed specific interactions in the glutathione S-transferase (GST) pull-down assay. An antibody to KHC specifically co-immunoprecipitated Frt-h and Frt-l from mouse brain extracts. These results suggest the kinesin 1 motor protein may transport the ferritin complex in cells.

• Journal of Life Science
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• v.33 no.1
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• pp.1-7
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• 2023

Intracellular cargo transport is mediated by molecular motor proteins, such as kinesin and cytoplasmic dynein. Kinesins make up a large subfamily of molecular motors. Kinesin-1 is a plus-end-directed molecular motor protein that moves various cargoes, such as organelles, protein complexes, and mRNAs, along a microtubule track. It consists of the kinesin superfamily protein (KIF) 5A, 5B, and 5C (also called kinesin heavy chains) and kinesin light chains (KLCs). Kinesin-1 interacts with many different binding proteins through its carboxyl (C)-terminal region of KIF5s and KLCs, but their binding proteins have not yet been fully identified. In this study, a yeast two-hybrid assay was used to identify the proteins that interact with the KIF5A specific C-terminal region. The assay revealed an interaction between KIF5A and glutamate-rich 4 (ERICH4). ERICH4 bound to the KIF5A specific the C-terminal region but did not interact with the C-terminal region of KIF5B or KIF3A (a motor protein of kinesin-2). In addition, KIF5A did not interact with another isoform, ERICH1. Glutathione S-transferase (GST) pull-downs showed that KIF5A interacts with GST-ERICH4 and GST-ERICH4-amino (N)-terminal but not with GST-ERICH4-C or GST alone. When co-expressed in HEK-293T cells, ERICH4 co-localized with KIF5A and co-immunoprecipitated with KIF5A and KLC but not KIF3B. Together, our findings suggest that ERICH4 is capable of binding to KIF5A and that it may serve as an adaptor protein that links kinesin-1 with cargo.

• Journal of Life Science
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• v.18 no.8
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• pp.1059-1065
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• 2008

KIF21A is a member of the Kinesin superfamily proteins (KIFs), which are microtubule-dependent molecular motors, anterograde axonal transporters of cargoes. Recently, congenital fibrosis of the extraocular muscles 1 (CFEOM1) has been shown to result from a small number of recurrent heterozygous missense mutations of KIF21A. CFEOM1 results from the inability of mutated KIF21A to successfully deliver cargoes to the development of the occulo-motor neuron or neuromuscular junction. Here, we used an yeast two-hybrid system to identify a protein that interacts with the WD-40 repeat domain of KIF21A and found a specific interaction with Purkinje cell protein-2 (Pcp-2), a small protein also known as L7. Pcp-2 protein bound to the WD-40 domain of KIF21A and KIF21B but not to other KIFs in yeast two-hybrid assays. In addition, this specific interaction was also observed in the glutathione S-transferase pull-down assay. An antibody to Pcp-2 specifically co-immunoprecipitated KIF21A associated with Pcp-2 from mouse brain extracts. These results suggest that Pcp-2 may be involved in the KIF21A-mediated transport as a KIF21A adaptor protein.