title: Dissect Kif5b in nuclear positioning during myogenesis: the light chain binding domain and the autoinhibitory peptide are both indispensable.
abstract: The microtubule motor kinesin-1 is responsible for the nuclear positioning during myogenesis. Here we show that the coiled-coil stalk/tail domain containing the kinesin light chain (KLC) binding sites targets to the perinuclear region like endogenous Kif5b, while the globular tail domain cannot. To investigate which fragments of kinesin heavy chain (Kif5b) is responsible for the myonuclear positioning, we transfect Kif5b expression constructs into Kif5b deficient myoblasts and test their ability to rescue the myonuclear phenotype. We find that the KLC binding domain and the autoinhibitory peptide in the globular tail region are both indispensable for the nuclear membrane localization of Kif5b and the kinesin-1-mediated myonuclear positioning. These results suggest that while the KLC binding domain may directly targets Kif5b to the myonuclear membrane, the autoinhibitory peptide may play an indirect role in regulating the kinesin-1-mediated myonuclear positioning.
authors: Department of Biochemistry, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong. wangzai81@hotmail.com
authors: Zai
authors: Z
authors: Wang
authors: Wenqian
authors: W
authors: Xue
authors: Xiuling
authors: X
authors: Li
authors: Raozhou
authors: R
authors: Lin
authors: Ju
authors: J
authors: Cui
authors: Jian-Dong
authors: JD
authors: Huang
mesh_terms: D000818:Animals; D002467:Cell Nucleus / Q000378:metabolism*; D002478:Cells, Cultured; D016547:Kinesins / Q000235:genetics / Q000378:metabolism*; D008565:Membrane Proteins / Q000378:metabolism; D051379:Mice; D018345:Mice, Knockout; D024510:Muscle Development; D032448:Myoblasts, Skeletal / Q000378:metabolism*; D009685:Nuclear Envelope / Q000378:metabolism; D049790:Nuclear Export Signals; D009687:Nuclear Proteins / Q000378:metabolism; D017434:Protein Structure, Tertiary
chemical_list: D008565:Membrane Proteins; D049790:Nuclear Export Signals; D009687:Nuclear Proteins; C539339:nesprin 4 protein, mouse; C475469:Kif5b protein, mouse; D016547:Kinesins