Rosenthal fibers contain ubiquitinated alpha B-crystallin.

The vertebrate lens protein, alpha B-crystallin, is a major component of Rosenthal fibers (RFs) inclusion in astrocytes in Alexander's disease. Antibodies to ubiquitin bind to RFs, but it is not known whether the ubiquitin associated with RFs is bound to a specific protein or proteins, and if so, what the identity of the conjugates is. The authors have analyzed the proteins of RFs from Alexander's disease and have found mono- and polyubiquitinated conjugates of alpha B-crystallin.