Unique characteristics of ubiquitin-bonded complex play a pathological role in dentatorubral-pallidoluysian atrophy.

Abnormal complex formation of dentatorubral-pallidoluysian atrophy (DRPLA) protein and pathological ubiquitination of abnormal complex are two pathological processes involved in DRPLA neurodegeneration. Pathological ubiquitination and solubility in SDS and reducing agent are two unique characteristics of the DRPLA protein complex. Ubiquitination of abnormal DRPLA protein complex in DRPLA brain tissue is heat-resistant and stronger than that in control brain tissue. Pathological ubiquitination of DRPLA protein complex correlates with the onset of symptoms and the size of an expanded glutamine repeat in brain tissue of patients with DRPLA. Pathological ubiquitination plays an important role in DRPLA pathology. DRPLA protein complex is water-insoluble but soluble in SDS and reducing agent, and displays no difference in water insolubility between control and DRPLA brain tissue. Abnormal insoluble complex formation is not developed by a qualitative change in water insolubility of DRPLA protein complex but is developed by a spontaneous accumulation of an abnormally large amount of the DRPLA protein complex. Copyright 1999 Academic Press.