The genomic sequence of the human CLN3 gene, which is defective in juvenile onset neuronal ceroid lipofuscinosis (Batten disease) is being delineated using a variety of methods.
Pulse-chase labelling of fibroblasts and lymphoblastoid cell lines with [35S]cysteine revealed the presence of lipid [35S]cysteine material in CLN1 fibroblasts and not in controls, CLN2 or CLN3 patients or other patients with lipidosis.
BTN1, a yeast gene corresponding to the human gene responsible for Batten's disease, is not essential for viability, mitochondrial function, or degradation of mitochondrial ATP synthase.
The Saccharomyces cerevisiae gene BTN1, encodes a 408 amino acid putative integral membrane protein, which is 39% identical and 59% similar to the human Cln3p, whose mutant forms are responsible for Batten's disease and for a diminished degradation of mitochondrial ATPase synthase subunit c. Disruption experiments established that Btn1p is not essential for viability, mitochondrial function, or degradation of mitochondrial ATP synthase in yeast.
Thus, a single point mutation at residue 295 of the CLN3 protein in protracted JNCL may underlie the phenotype in this form, which differs from that in classic JNCL.
Thus, a single point mutation at residue 295 of the CLN3 protein in protracted JNCL may underlie the phenotype in this form, which differs from that in classic JNCL.
Coding sequence and exon/intron organization of the canine CLN3 (Batten disease) gene and its exclusion as the locus for ceroid-lipofuscinosis in English setter dogs.
Although the CLN3 gene for Batten disease, the most common inherited neurovisceral storage disease of childhood, was identified in 1995, the function of the corresponding protein still remains elusive.
Furthermore, the severity of Batten disease in humans and the degree of ANP resistance in yeast are related when the equivalent amino acid replacements in Cln3p and Btn1p are compared.
Classic late-infantile NCL (Jansky-Bielschowsky disease) is caused by mutations in a gene encoding a pepstatin-insensitive lysosomal peptidase (CLN2 on chromosome 11p15), and juvenile-onset NCL (Batten disease) is caused by mutations in a gene encoding a 438-amino-acid membrane protein (CLN3 on chromosome 16p12) of unknown function.
There are a number of clinically and genetically distinct forms of ceroid-lipofuscinosis, the most common of which is the juvenile type, also known as Batten disease and CLN3.