Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.4.23.5 (cathepsin D)
 4,130 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We have isolated and characterized a human genomic clone for a lysosomal enzyme gene. The start point of transcription was identified using primer extension of poly(A)+ mRNA. This genomic clone is specific for human alpha-galactosidase A, and it includes sequences for the promoter, complete signal peptide, first exon, and part of the first intron. Direct and inverted repeat elements of 10, 11, 16, 19, and 22 nucleotides (nt) flank the promoter site. A (GA)n repeat element of approx. 60 nt with strong homology to similar elements identified in several species is located upstream from the promoter. A GGGCGG site specific for DNA-binding protein Sp1 is located near a CAAT box, and the CCGCCC inverted repeat of the Sp1 binding sequence is located by the TATA box. The sequence immediately flanking the ATG start codon of the human alpha-galactosidase A is highly homologous to sequences flanking the ATG start codons of the other human lysosomal hydrolases for which sequence information is available (beta-glucocerebrosidase, cathepsin B, cathepsin D, and beta-hexosaminidase alpha chain), but not for any of the other 133 human signal peptides examined. Our analysis also reveals that conversion of the propeptide to the mature enzyme involves cleavage of a C-terminal rather than an N-terminal fragment. This information about the normal alpha-galactosidase A gene will be useful for comparison to data obtained from patients with Fabry disease, who are characterized by a deficiency of this enzyme. This is the first genomic clone described to date for any lysosomal enzyme, and it establishes a reference for future analyses of the molecular events that mediate the expression of this important class of enzymes.
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PMID:A genomic clone containing the promoter for the gene encoding the human lysosomal enzyme, alpha-galactosidase A. 289 62

Heterozygous loss-of-function mutations in the progranulin (GRN) gene and the resulting reduction of GRN levels is a common genetic cause for frontotemporal lobar degeneration (FTLD) with accumulation of TAR DNA-binding protein (TDP)-43. Recently, it has been shown that a complete GRN deficiency due to a homozygous GRN loss-of-function mutation causes neuronal ceroid lipofuscinosis (NCL), a lysosomal storage disorder. These findings suggest that lysosomal dysfunction may also contribute to some extent to FTLD. Indeed, Grn(-/-) mice recapitulate not only pathobiochemical features of GRN-associated FTLD-TDP (FTLD-TDP/GRN), but also those which are characteristic for NCL and lysosomal impairment. In Grn(-/-) mice the lysosomal proteins cathepsin D (CTSD), LAMP (lysosomal-associated membrane protein) 1 and the NCL storage components saposin D and subunit c of mitochondrial ATP synthase (SCMAS) were all found to be elevated. Moreover, these mice display increased levels of transmembrane protein (TMEM) 106B, a lysosomal protein known as a risk factor for FTLD-TDP pathology. In line with a potential pathological overlap of FTLD and NCL, Ctsd(-/-) mice, a model for NCL, show elevated levels of the FTLD-associated proteins GRN and TMEM106B. In addition, pathologically phosphorylated TDP-43 occurs in Ctsd(-/-) mice to a similar extent as in Grn(-/-) mice. Consistent with these findings, some NCL patients accumulate pathologically phosphorylated TDP-43 within their brains. Based on these observations, we searched for pathological marker proteins, which are characteristic for NCL or lysosomal impairment in brains of FTLD-TDP/GRN patients. Strikingly, saposin D, SCMAS as well as the lysosomal proteins CTSD and LAMP1/2 are all elevated in patients with FTLD-TDP/GRN. Thus, our findings suggest that lysosomal storage disorders and GRN-associated FTLD may share common features.
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PMID:Common pathobiochemical hallmarks of progranulin-associated frontotemporal lobar degeneration and neuronal ceroid lipofuscinosis. 2461 11