Abnormal gene product identified in hereditary dentatorubral−pallidoluysian atrophy (DRPLA) brain

Dentatorubral−pallidoluysian atrophy (DRPLA) is associated with the expansion of an unstable GAG repeat. Using antibodies against a synthetic peptide corresponding to the sequence of the DRPLA gene product C terminus, we have identified the DRPLA gene product in normal human brains as a 190 kD protein. We also find a larger 205 kD protein specifically in DRPLA brains. Immunohistochemically, the DRPLA gene product is observed mainly in the neuronal cytoplasm. Our results demonstrate the existence of the expanded GAG repeat gene product and support the possibility that the expanded CAG−encoded polyglutamine stretch may participate in the pathological process of the similar trinucleotide repeat diseases.

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