title: Characterizing KIF16B in neurons reveals a novel intramolecular "stalk inhibition" mechanism that regulates its capacity to potentiate the selective somatodendritic localization of early endosomes.
abstract: An organelle's subcellular localization is closely related to its function. Early endosomes require localization to somatodendritic regions in neurons to enable neuronal morphogenesis, polarized sorting, and signal transduction. However, it is not known how the somatodendritic localization of early endosomes is achieved. Here, we show that the kinesin superfamily protein 16B (KIF16B) is essential for the correct localization of early endosomes in mouse hippocampal neurons. Loss of KIF16B induced the aggregation of early endosomes and perturbed the trafficking and functioning of receptors, including the AMPA and NGF receptors. This defect was rescued by KIF16B, emphasizing the critical functional role of the protein in early endosome and receptor transport. Interestingly, in neurons expressing a KIF16B deletion mutant lacking the second and third coiled-coils of the stalk domain, the early endosomes were mistransported to the axons. Additionally, the binding of the motor domain of KIF16B to microtubules was inhibited by the second and third coiled-coils (inhibitory domain) in an ATP-dependent manner. This suggests that the intramolecular binding we find between the inhibitory domain and motor domain of KIF16B may serve as a switch to control the binding of the motor to microtubules, thereby regulating KIF16B activity. We propose that this novel autoregulatory "stalk inhibition" mechanism underlies the ability of KIF16B to potentiate the selective somatodendritic localization of early endosomes.
authors: Department of Molecular and Cell Biology and Department of Molecular Structure and Dynamics, Graduate School of Medicine, University of Tokyo, Tokyo 113-0033, Japan, and.
authors: Atena
authors: http://orcid.org/0000-0003-4662-1841
authors: A
authors: Farkhondeh
authors: Department of Molecular and Cell Biology and Department of Molecular Structure and Dynamics, Graduate School of Medicine, University of Tokyo, Tokyo 113-0033, Japan, and.
authors: Shinsuke
authors: S
authors: Niwa
authors: Department of Molecular and Cell Biology and Department of Molecular Structure and Dynamics, Graduate School of Medicine, University of Tokyo, Tokyo 113-0033, Japan, and.
authors: Yosuke
authors: Y
authors: Takei
authors: Department of Molecular and Cell Biology and Department of Molecular Structure and Dynamics, Graduate School of Medicine, University of Tokyo, Tokyo 113-0033, Japan, and Center of Excellence in Genome Medicine Research, King Abdulaziz University, Jeddah 21589, Saudi Arabia hirokawa@m.u-tokyo.ac.jp.
authors: Nobutaka
authors: N
authors: Hirokawa
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D003712:Dendrites / Q000378:metabolism*; D011992:Endosomes / Q000378:metabolism*; D055785:Gene Knockdown Techniques; D006624:Hippocampus / Q000378:metabolism; D006801:Humans; D016547:Kinesins / Q000235:genetics / Q000502:physiology*; D051379:Mice; D008870:Microtubules / Q000378:metabolism; D009474:Neurons / Q000166:cytology* / Q000378:metabolism*; D011485:Protein Binding / Q000235:genetics / Q000502:physiology; D054730:Protein Interaction Domains and Motifs / Q000235:genetics / Q000502:physiology; D021381:Protein Transport / Q000235:genetics / Q000502:physiology; D020800:Receptor, Nerve Growth Factor / Q000378:metabolism; D018091:Receptors, AMPA / Q000378:metabolism; D017384:Sequence Deletion
chemical_list: D020800:Receptor, Nerve Growth Factor; D018091:Receptors, AMPA; C555883:kinesin family member 16B; D016547:Kinesins
keywords: KIF16B; early endosome; neurons; receptor trafficking; stalk inhibition