[Batten disease (Neuronal ceroid lipofuscinoses)--accumulation of ATP synthase subunit c caused by the delay of lysosomal degradation]

Abstract

The neuronal ceroid lipofuscinoses (NCLs) represent a group of recessively inherited neurogenerative diseases of infants, children, and young adults that leads to blindness, seizures, dementia, and premature death. These diseases are pathologically characterized by a massive lysosomal storage of autofluorescent lipopigments in neurons and a wide variety of extraneuronal cells. Linkage studies have shown localization of the infantile disease to chromosome region 1p32 the juvenile onset disease to chromosome 16p12.1-p11.2 and a variant form of late infantile form to chromosome 13q21.1-q32. Recently, protein sequencing and immunochemical studies have identified subunit c of the mitochondrial ATP synthase as a major component of the storage material in the late infantile and juvenile types of NCL, and SAPs in infantile type of NCL. Immunolocalization studies demonstrated a dot-like staining of subunit c in the cells with NCL and the staining pattern of subunit c was similar to that of a lysosomal membrane marker, 1gp120. Pulse-chase experiments revealed that a specific failure occurs in the degradation of subunit c in lysosomes whereas its transport into mitochondria and subsequent sequestration into lysosomes are apparently normal.