Alpha B-crystallin is associated with intermediate filaments in astrocytoma cells.
Alpha B-crystallin, a major protein of the vertebrate lens and a member of the small heat shock protein family, is expressed in non-lenticular tissues, including the central nervous system, where it is found mainly in glia. In Rosenthal fibers (RF), astrocytic inclusions that accumulate in Alexander's Disease, alpha B-crystallin is found with hsp27 and skeins of intermediate filaments (IF) of the GFAP and vimentin types. We have investigated the association between IF and alpha B-crystallin in a human astrocytoma cell line, U-373MG, which expresses alpha B-crystallin. Cytoskeletal preparations contained alpha B-crystallin, and a filamentous pattern in which alpha B-crystallin co-localized with GFAP and vimentin by double label immunofluorescence. Immuno-electronmicroscopy confirmed the localization to IF. GFAP isolated from bovine brain and re-assembled, was associated with alpha B-crystallin. Thus, a proportion of alpha B-crystallin in astroglia is associated with IF, and this association may be critical in the formation of RF.
Wisniewski
T
T
Department of Neurology, New York University Medical Center, NY 10016, USA.
Goldman
J E
JE
D000818:Animals; D001254:Astrocytoma / Q000737:chemistry / Q000378:metabolism*; D002417:Cattle; D002458:Cell Fractionation; D003459:Crystallins / Q000737:chemistry / Q000378:metabolism*; D019084:Fluorescent Antibody Technique, Indirect; D005904:Glial Fibrillary Acidic Protein / Q000378:metabolism; D006801:Humans; D007382:Intermediate Filaments / Q000737:chemistry / Q000378:metabolism*; D011485:Protein Binding; D051381:Rats; D014407:Tumor Cells, Cultured
D003459:Crystallins; D005904:Glial Fibrillary Acidic Protein