Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P17174 (aspartate aminotransferase)
 14,872 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Lysosomal degradation of intracellular proteins during serum withdrawal is stimulated by a member of the 70-kDa heat shock protein (hsp70) family (Chiang, H.-L., Terlecky, S. R., Plant, C. P., and Dice, J. F. (1989) Science 246, 382-385). This hsp70, isolated by affinity chromatography with RNase S-peptide-Sepharose, is referred to as the 73-kDa peptide recognition protein (prp73). We now report that prp73 binds to several proteins and peptides whose degradative rates are increased during serum withdrawal. prp73 also binds to the pentapeptide, KFERQ, and more weakly to most modified RNase S-peptide derivatives with a single amino acid substitution within the KFERQ sequence. Taken together, these results suggest that prp73 binds to a variety of proteins at peptide regions biochemically related to KFERQ. Three lines of evidence indicate that prp73 is the heat shock cognate protein of 73 kDa (hsc73): (a) among five hsp70s tested, hsc73 binds to RNase S-peptide most avidly, (b) both prp73 and hsc73 also bind to RNase A and aspartate aminotransferase but not to ovalbumin, lysozyme, or ubiquitin, and (c) both prp73 and hsc73 promote uptake and degradation of [3H] RNase S-peptide by lysosomes in vitro, while three other hsp70s are without activity in this assay.
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PMID:Protein and peptide binding and stimulation of in vitro lysosomal proteolysis by the 73-kDa heat shock cognate protein. 157 55

The activities of alanine aminotransferase (ES 2.6.1.2), aspartate aminotransferase (EC 2.6.1.1) and monoaminoxidase (EC 1.4.3.4) in the liver nuclei and mitochondria of human fes rises gradually beginning from the early periods of the antenatal development till birth and reaches the highest value in the last month of the fetus intra-uterine life. The monoaminoxidase activity is found in the liver nuclei of 21-32-week human feti. The activity of RNase (EC 2.7.7.16) and DNase (EC 3.1.4.5) in the liver nuclei is 10 and 15 times as low, respectively, by the 40th week of development, and 1.5 times as low in mitochondria.
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PMID:[Comparative characteristics of the activity of enzyme systems for nitrogen metabolism in the liver of human fetuses during embryogenesis]. 713 1

We have studied the expression and regulation of the rat testis cytosolic aspartate aminotransferase gene. The cytosolic aspartate aminotransferase activity was 5-fold lower in the testis than in the liver and kidney. A 1.9-kilobase mRNA form was detected in the rat testis in contrast to the 2.1- and 1.8-kilobase forms present in other organs. Using Northern blot and S1 mapping analyses, we found that the proximal polyadenylation site was almost exclusively used in the testis as opposed to other organs where the distal site was preferentially used. RNase protection and primer extension analysis showed that transcription was initiated at multiple sites in all organs, but the pattern of those start sites was different in the testis; in particular, a novel transcription start site was specifically detected in this organ (at position -115 from the translation start site). This site was first observed in 29-day-old rats and was maximally utilized in the adult testis. DNase I footprinting using testis nuclear extracts revealed the presence of three sites of DNA-protein interaction in the 250-base pair proximal promoter, a pattern similar to the one found using liver nuclear extracts. However, the proteins bound had different properties as shown by gel retardation experiments. We conclude that the pattern of transcription initiation and the polyadenylation site selection of a housekeeping gene can be tissue-specific.
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PMID:Testis-specific transcription start site in the aspartate aminotransferase housekeeping gene promoter. 817 62

During differentiation of mouse 3T3-L1 fibroblasts to an adipocyte phenotype, the mitochondrial isoform of aspartate aminotransferase accumulates on the plasma membrane. The determination of whether this reflects translation of an alternatively spliced message lacking the mitochondrial leader sequence required cloning of the enzyme's uncommon a allele, for which these cells are homozygous. The 1.4-kb cDNA sequence of the a allele was obtained from oligo-dT-primed reverse-transcriptase PCR products amplified from FVB mouse RNA. It differed from the b allele at only 2 bp and one amino acid. By contrast, gene-specific primers generated an additional 1.4-kb fragment that differed from the b allele by approximately 1% of nucleotides, encoding four amino acid substitutions. This sequence proved to represent a recently diverged processed pseudogene. The presence of such pseudogenes can complicate interpretation of expressed-sequence-tag data and single-nucleotide-polymorphism genotyping studies. Using probes derived from the a allele, RNase protection analyses indicated that only a single message for the enzyme was present in 3T3-L1 fibroblasts and adipocytes, despite differences in subcellular protein distribution.
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PMID:Mitochondrial aspartate aminotransferase: direction of a single protein with two distinct functions to two subcellular sites does not require alternative splicing of the mRNA. 1064 97