title: Cyclin-dependent kinase 5 increases perikaryal neurofilament phosphorylation and inhibits neurofilament axonal transport in response to oxidative stress.
abstract: Cyclin-dependent kinase 5 (cdk5) phosphorylates the high molecular weight neurofilament (NF) protein. Overexpression of cdk5 inhibits NF axonal transport and induces perikaryal accumulation of disordered phospho-NF cables. Experimental and clinical motor neuron disease is characterized by oxidative stress, increased cdk5 activity, and accumulation of phospho-NFs within perikarya or proximal axons. Because oxidative stress increases cdk5 activity in experimental motor neuron disease, we examined whether oxidative stress induced cdk5-mediated NF phosphorylation. Treatment of cultured neuronal cells with hydrogen peroxide inhibited axonal transport of green fluorescent protein-tagged NF subunits and induced perikaryal accumulation of NF phosphoepitopes normally confined to axons. These effects were prevented by treatment with the cdk5 inhibitor roscovitine or transfection with a construct expressing the endogenous cdk5 inhibitor peptide. These findings indicate that oxidative stress can compromise NF dynamics via hyperactivation of cdk5 and suggest that antioxidants may alleviate multiple aspects of neuropathology in motor neuron disease.
authors.affiliation: Center for Cellular Neurobiology and Neurodegeneration Research, Department of Biological Sciences, University of Massachusetts Lowell, One University Avenue, 01854, USA. Thomas_Shea@uml.edu
authors.forename: Thomas B
authors.initials: TB
authors.lastname: Shea
authors.forename: Ya-Li
authors.initials: YL
authors.lastname: Zheng
authors.forename: Daniela
authors.initials: D
authors.lastname: Ortiz
authors.forename: Harish C
authors.initials: HC
authors.lastname: Pant
mesh_terms: D000818:Animals; D001370:Axonal Transport / Q000187:drug effects / Q000502:physiology*; D002478:Cells, Cultured; D002642:Chick Embryo; D051360:Cyclin-Dependent Kinase 5; D018844:Cyclin-Dependent Kinases / Q000187:drug effects / Q000378:metabolism*; D005727:Ganglia, Spinal / Q000166:cytology / Q000187:drug effects / Q000201:enzymology*; D006861:Hydrogen Peroxide / Q000494:pharmacology; D016900:Neurofilament Proteins / Q000187:drug effects / Q000378:metabolism*; D009474:Neurons / Q000187:drug effects / Q000201:enzymology*; D016877:Oxidants / Q000494:pharmacology; D018384:Oxidative Stress / Q000502:physiology*; D010766:Phosphorylation / Q000187:drug effects
chemical_list: D016900:Neurofilament Proteins; D016877:Oxidants; D006861:Hydrogen Peroxide; D051360:Cyclin-Dependent Kinase 5; D018844:Cyclin-Dependent Kinases