TorsinB--perinuclear location and association with torsinA.
The torsins comprise a four-member family of AAA+ chaperone proteins, including torsinA, torsinB, torp2A and torp3A in humans. Mutations in torsinA underlie early onset torsion dystonia, an autosomal dominant, neurologically based movement disorder. TorsinB is highly homologous to torsinA with its gene adjacent to that for torsinA on human chromosome 9q34. Antibodies have been generated which can distinguish torsinA and torsinB from each other, and from the torps in human and rodent cells. TorsinB (approximately MW 38 kDa), like torsinA ( approximately MW 37 kDa), is an N-glycosylated protein and both reside primarily in the endoplasmic reticulum (ER) and nuclear envelope in cultured cells. Immunoprecipitation studies in cultured cells and human brain tissue indicate that torsinA and torsinB are associated with each other in cells. Overexpression of both wild-type torsinB and mutant torsinA lead to enrichment of the protein in the nuclear envelope and formation of large cytoplasmic inclusions. We conclude that torsinB and torsinA are localized in overlapping cell compartments within the same protein complex, and thus may carry out related functions in vivo.
Hewett
Jeffrey W
JW
Departments of Neurology and Radiology, Molecular Neurogenetics Unit, Massachusetts General Hospital, 13th Street, Charlestown, MA 02129, USA.
Kamm
Christoph
C
Boston
Heather
H
Beauchamp
Roberta
R
Naismith
Teri
T
Ozelius
Laurie
L
Hanson
Phyllis I
PI
Breakefield
Xandra O
XO
Ramesh
Vijaya
V
D000818:Animals; D000918:Antibody Specificity; D015153:Blotting, Western; D001921:Brain / Q000166:cytology / Q000378:metabolism*; D001923:Brain Chemistry; D002352:Carrier Proteins / Q000032:analysis / Q000378:metabolism*; D002451:Cell Compartmentation / Q000502:physiology; D004721:Endoplasmic Reticulum / Q000378:metabolism; D006031:Glycosylation; D006801:Humans; D007150:Immunohistochemistry; D007668:Kidney / Q000166:cytology / Q000378:metabolism; D051379:Mice; D018832:Molecular Chaperones / Q000032:analysis / Q000378:metabolism*; D009447:Neuroblastoma / Q000378:metabolism* / Q000473:pathology; D009685:Nuclear Envelope / Q000378:metabolism* / Q000648:ultrastructure; D011233:Precipitin Tests
D002352:Carrier Proteins; C491548:Dyt1 protein, mouse; D018832:Molecular Chaperones; C108175:TOR1A protein, human; C491547:TOR1B protein, human; C400325:Tor1b protein, mouse