Biochemical characterization of torsinB.
Mutations in torsinA, a member of the AAA+ family of ATPases, are associated with early onset-dystonia. A closely related homologue, torsinB, has also been described but the significance of this second form is not clear. Here, we demonstrate that in transfected cells, torsinB has similar electrophoretic mobility to torsinA but is more basic consistent with predictions from the cDNA sequence. Like torsinA, torsinB is glycosylated and localized to PDI-positive structures in cells. However, torsinB unlike torsinA has a tendency to form intracellular inclusions when expressed at similar levels. We were able to confirm previous reports that torsinA is present in brainstem Lewy bodies, but we saw no torsinB-like immunoreactivity in the same structures. These results show that torsins A and B are similar proteins, although there are differences in the abundance of the two homologues and in their recruitment into Lewy bodies.
Department of Neuroscience, Mayo Clinic Jacksonville, 4500 San Pablo Road, Jacksonville, FL 32224, USA.
Casey
C
O'Farrell
Paul J
PJ
Lockhart
Sarah
S
Lincoln
Michael
M
De Lucia
Andrew B
AB
Singleton
Dennis W
DW
Dickson
Mark R
MR
Cookson
D000595:Amino Acid Sequence; D015152:Blotting, Northern / Q000379:methods; D001921:Brain / Q000378:metabolism; D001923:Brain Chemistry; D002352:Carrier Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D002460:Cell Line; D024202:Electrophoretic Mobility Shift Assay / Q000379:methods; D004622:Embryo, Mammalian; D015870:Gene Expression; D006031:Glycosylation; D006801:Humans; D007150:Immunohistochemistry / Q000379:methods; D017953:Isocyanates; D016631:Lewy Bodies / Q000378:metabolism; D018613:Microscopy, Confocal; D018832:Molecular Chaperones / Q000235:genetics / Q000378:metabolism; D009154:Mutation; D012333:RNA, Messenger / Q000096:biosynthesis; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods; D014162:Transfection
C476736:2-methylpentane-diisocyanate; D002352:Carrier Proteins; D017953:Isocyanates; D018832:Molecular Chaperones; D012333:RNA, Messenger; C108175:TOR1A protein, human; C491547:TOR1B protein, human; C400325:Tor1b protein, mouse