title: Drosophila katanin-60 depolymerizes and severs at microtubule defects.
abstract: Microtubule (MT) length and location is tightly controlled in cells. One novel family of MT-associated proteins that regulates MT dynamics is the MT-severing enzymes. In this work, we investigate how katanin (p60), believed to be the first discovered severing enzyme, binds and severs MTs via single molecule total internal reflection fluorescence microscopy. We find that severing activity depends on katanin concentration. We also find that katanin can remove tubulin dimers from the ends of MTs, appearing to depolymerize MTs. Strikingly, katanin localizes and severs at the interface of GMPCPP-tubulin and GDP-tubulin suggesting that it targets to protofilament-shift defects. Finally, we observe that binding duration, mobility, and oligomerization are ATP dependent.
authors.affiliation: Department of Physics, University of Massachusetts-Amherst, Amherst, Massachusetts, USA.
authors.forename: Juan Daniel
authors.initials: JD
authors.lastname: Díaz-Valencia
authors.forename: Margaret M
authors.initials: MM
authors.lastname: Morelli
authors.forename: Megan
authors.initials: M
authors.lastname: Bailey
authors.forename: Dong
authors.initials: D
authors.lastname: Zhang
authors.forename: David J
authors.initials: DJ
authors.lastname: Sharp
authors.forename: Jennifer L
authors.initials: JL
authors.lastname: Ross
mesh_terms: D000251:Adenosine Triphosphatases / Q000737:chemistry / Q000378:metabolism*; D000255:Adenosine Triphosphate / Q000494:pharmacology; D000818:Animals; D016367:Baculoviridae / Q000187:drug effects / Q000378:metabolism; D029721:Drosophila Proteins / Q000737:chemistry / Q000378:metabolism*; D004331:Drosophila melanogaster / Q000187:drug effects / Q000378:metabolism*; D005453:Fluorescence; D049452:Green Fluorescent Proteins / Q000378:metabolism; D006153:Guanosine Diphosphate / Q000378:metabolism; D006160:Guanosine Triphosphate / Q000031:analogs & derivatives / Q000378:metabolism; D000074201:Katanin; D008870:Microtubules / Q000187:drug effects / Q000378:metabolism*; D008954:Models, Biological; D017239:Paclitaxel / Q000494:pharmacology; D038761:Photobleaching / Q000187:drug effects; D058105:Polymerization / Q000187:drug effects; D011485:Protein Binding / Q000187:drug effects; D020836:Protein Structure, Quaternary; D017434:Protein Structure, Tertiary; D021381:Protein Transport / Q000187:drug effects; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D014404:Tubulin / Q000378:metabolism
chemical_list: D029721:Drosophila Proteins; C519702:Kat60 protein, Drosophila; D011993:Recombinant Fusion Proteins; D014404:Tubulin; D006153:Guanosine Diphosphate; D049452:Green Fluorescent Proteins; C004805:5'-guanylylmethylenebisphosphonate; D006160:Guanosine Triphosphate; D000255:Adenosine Triphosphate; D000251:Adenosine Triphosphatases; D000074201:Katanin; D017239:Paclitaxel