title: The C-terminal α-helix of SPAS-1, a Caenorhabditis elegans spastin homologue, is crucial for microtubule severing.
abstract: Spastin belongs to the meiotic subfamily, together with Vps4/SKD1, fidgetin and katanin, of AAA (ATPases associated with diverse cellular activities) proteins, and functions in microtubule severing. Interestingly, all members of this subgroup specifically contain an additional α-helix at the very C-terminal end. To understand the function of the C-terminal α-helix, we characterised its deletion mutants of SPAS-1, a Caenorhabditis elegans spastin homologue, in vitro and in vivo. We found that the C-terminal α-helix plays essential roles in ATP binding, ATP hydrolysing and microtubule severing activities. It is likely that the C-terminal α-helix is required for cellular functions of members of meiotic subgroup of AAA proteins, since the C-terminal α-helix of Vps4 is also important for assembly, ATPase activity and in vivo function mediated by ESCRT-III complexes.
authors.affiliation: Department of Molecular Cell Biology, Institute of Molecular Embryology and Genetics, Kumamoto University, 2-2-1 Honjo, Kumamoto 860-0811, Japan.
authors.forename: Akinobu
authors.initials: A
authors.lastname: Onitake
authors.forename: Yuka
authors.initials: Y
authors.lastname: Matsushita-Ishiodori
authors.forename: Ai
authors.initials: A
authors.lastname: Johjima
authors.forename: Masatoshi
authors.initials: M
authors.lastname: Esaki
authors.forename: Teru
authors.initials: T
authors.lastname: Ogura
authors.forename: Kunitoshi
authors.initials: K
authors.lastname: Yamanaka
mesh_terms: D000818:Animals; D029742:Caenorhabditis elegans Proteins / Q000737:chemistry* / Q000378:metabolism*; D002460:Cell Line; D002850:Chromatography, Gel; D006801:Humans; D008870:Microtubules / Q000378:metabolism*; D024101:Mitochondrial Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D029589:Seminal Plasma Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D013050:Spectrometry, Fluorescence
chemical_list: D029742:Caenorhabditis elegans Proteins; D024101:Mitochondrial Proteins; C475607:SPATA19 protein, human; D029589:Seminal Plasma Proteins