Spastin oligomerizes into a hexamer and the mutant spastin (E442Q) redistribute the wild-type spastin into filamentous microtubule.
Spastin, a member of the ATPases associated with various cellular activities (AAA) family of proteins, is the most frequently mutated in hereditary spastic paraplegia. The defining feature of the AAA proteins is a structurally conserved AAA domain which assembles into an oligomer. By chemical cross-linking and gel filtration chromatography, we show that spastin oligomerizes into a hexamer. Furthermore, to gain a comprehensive overview of the oligomeric structure of spastin, we generated a structural model of the AAA domain of spastin using template structure of VPS4B and p97/VCP. The generated model of spastin provided us with a framework to classify the identified missense mutations in the AAA domain from hereditary spastic paraplegia patients into different structural/functional groups. Finally, through co-localization studies in mammalian cells, we show that E442Q mutant spastin acts in a dominant negative fashion and causes redistribution of both wild-type spastin monomer and spastin interacting protein, RTN1 into filamentous microtubule bundles.
Pantakani
D V Krishna
DV
Institute of Human Genetics, University of Goettingen, Goettingen, Germany.
Swapna
Lakshmipuram S
LS
Srinivasan
Narayanaswamy
N
Mannan
Ashraf U
AU
D000074183:ATPases Associated with Diverse Cellular Activities; D000251:Adenosine Triphosphatases / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D000818:Animals; D002850:Chromatography, Gel / Q000379:methods; D056827:Endosomal Sorting Complexes Required for Transport; D018698:Glutamic Acid / Q000235:genetics*; D005973:Glutamine / Q000235:genetics*; D049452:Green Fluorescent Proteins / Q000378:metabolism; D006801:Humans; D047468:Immunoprecipitation / Q000379:methods; D051379:Mice; D008870:Microtubules / Q000378:metabolism*; D008958:Models, Molecular; D009154:Mutation; D041681:NIH 3T3 Cells; D009419:Nerve Tissue Proteins / Q000378:metabolism; D009687:Nuclear Proteins / Q000737:chemistry / Q000378:metabolism; D017434:Protein Structure, Tertiary; D021381:Protein Transport / Q000235:genetics; D000074181:Spastin; D014162:Transfection / Q000379:methods; D033921:Vesicular Transport Proteins / Q000737:chemistry / Q000378:metabolism
D056827:Endosomal Sorting Complexes Required for Transport; D009419:Nerve Tissue Proteins; D009687:Nuclear Proteins; C081781:RTN1 protein, human; D033921:Vesicular Transport Proteins; D005973:Glutamine; D049452:Green Fluorescent Proteins; D018698:Glutamic Acid; D000251:Adenosine Triphosphatases; C404942:p97 ATPase; D000074183:ATPases Associated with Diverse Cellular Activities; D000074181:Spastin; C490304:VPS4B protein, human; C400283:SPAST protein, human