title: The microtubule-severing protein fidgetin acts after dendrite injury to promote their degeneration.
abstract: After being severed from the cell body, axons initiate an active degeneration program known as Wallerian degeneration. Although dendrites also seem to have an active injury-induced degeneration program, no endogenous regulators of this process are known. Because microtubule disassembly has been proposed to play a role in both pruning and injury-induced degeneration, we used a Drosophila model to identify microtubule regulators involved in dendrite degeneration. We found that, when levels of fidgetin were reduced using mutant or RNA interference (RNAi) strategies, dendrite degeneration was delayed, but axon degeneration and dendrite pruning proceeded with normal timing. We explored two possible ways in which fidgetin could promote dendrite degeneration: (1) by acting constitutively to moderate microtubule stability in dendrites, or (2) by acting specifically after injury to disassemble microtubules. When comparing microtubule dynamics and stability in uninjured neurons with and without fidgetin, we could not find evidence that fidgetin regulated microtubule stability constitutively. However, we identified a fidgetin-dependent increase in microtubule dynamics in severed dendrites. We conclude that fidgetin acts after injury to promote disassembly of microtubules in dendrites severed from the cell body.
authors.affiliation: Department of Biochemistry and Molecular Biology and The Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, PA 16802, USA.
authors.forename: Juan
authors.initials: J
authors.lastname: Tao
authors.affiliation: Department of Biochemistry and Molecular Biology and The Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, PA 16802, USA.
authors.forename: Chengye
authors.initials: C
authors.lastname: Feng
authors.affiliation: Department of Biochemistry and Molecular Biology and The Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, PA 16802, USA mur22@psu.edu.
authors.forename: Melissa M
authors.identifier: 0000-0002-5021-4360
authors.initials: MM
authors.lastname: Rolls
mesh_terms: D000074183:ATPases Associated with Diverse Cellular Activities; D000107:Acetylation; D000818:Animals; D001369:Axons / Q000378:metabolism; D003712:Dendrites / Q000378:metabolism*; D029721:Drosophila Proteins / Q000378:metabolism*; D004331:Drosophila melanogaster / Q000378:metabolism; D008869:Microtubule-Associated Proteins; D008870:Microtubules / Q000378:metabolism*; D008954:Models, Biological; D009410:Nerve Degeneration / Q000378:metabolism* / Q000473:pathology*; D009687:Nuclear Proteins / Q000378:metabolism*; D034622:RNA Interference
chemical_list: D029721:Drosophila Proteins; D008869:Microtubule-Associated Proteins; D009687:Nuclear Proteins; D000074183:ATPases Associated with Diverse Cellular Activities; C519701:Fign protein, Drosophila
keywords: Dendrite degeneration; Dendrite pruning; Microtubule severing; Wallerian degeneration