Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:2.6.1.44 (AGT)
 770 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Primary hyperoxaluria type 1 (PH1) is an inborn error of metabolism resulting from a deficiency of alanine:glyoxylate aminotransferase (AGXT; EC 2.6.1.44). Most of the PH1 alleles detected in the Canary Islands carry the Ile-244 --> Thr (I244T) mutation in the AGXT gene, with 14 of 16 patients homozygous for this mutation. Four polymorphisms within AGXT and regional microsatellites also were shared in their haplotypes (AGXT*LTM), consistent with a founder effect. The consequences of these amino acid changes were investigated. Although I244T alone did not affect AGXT activity or subcellular localization, when present in the same protein molecule as Leu-11 --> Pro (L11P), it resulted in loss of enzymatic activity in soluble cell extracts. Like its normal counterpart, the AGXT*LTM protein was present in the peroxisomes but it was insoluble in detergent-free buffers. The polymorphism L11P behaved as an intragenic modifier of the I244T mutation, with the resulting protein undergoing stable interaction with molecular chaperones and aggregation. This aggregation was temperature-sensitive. AGXT*LTM expressed in Escherichia coli, as a GST-fusion protein, and in insect cells could be purified and retained enzymatic activity. Among various chemical chaperones tested in cell culture, betaine substantially improved the solubility of the mutant protein and the enzymatic activity in cell lysates. In summary, I244T, the second most common mutation responsible for PH1, is a protein conformational disease that may benefit from new therapies with pharmacological chaperones or small molecules to minimize protein aggregation.
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PMID:Primary hyperoxaluria type 1 in the Canary Islands: a conformational disease due to I244T mutation in the P11L-containing alanine:glyoxylate aminotransferase. 1277 26

Quantitative proteomics was used to reveal biochemical differences in kidneys of marine and freshwater three-spined sticklebacks. More than 1500 unambiguous proteins were identified, 106 of which are robustly co-translationally modified. Amino-terminal acetylation sites for 94 and proline hydroxylation sites for 12 proteins, including 4 protein disulfide isomerases having the consensus motif APWCGHCK, were determined. More than 1500 proteins were quantified by LC-MS/MS yielding 120 proteins with consistent population-specific abundance differences. Twenty-five of these were selected for validation by data-independent acquisition (DIA) and spectral library based MS2 quantitation. A dense biochemical network was revealed, which promotes the synthesis of the organic osmolytes betaine, sorbitol, trimethylamine oxid (TMAO), and urea. It contains 33 of 49 proteins that are elevated in marine compared to freshwater sticklebacks, including the most highly elevated proteins (dimethylaniline monooxygenase, alanine-glyoxylate aminotransferase, glycine N-methyltransferase). Freshwater stickleback kidneys contain elevated levels of proteolytic, cytoskeletal, extracellular matrix, and calcium signaling proteins. Proteins that are most elevated in freshwater sticklebacks are ES1 protein homolog, apoptosis-associated speck-like protein containing a CARD and caspase 1. Protein-abundance network analysis demonstrates significantly higher levels of synchronized abundance control in marine sticklebacks. The significance of these findings for biochemical diversification of renal function in marine and FW sticklebacks is discussed.
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PMID:Population-specific renal proteomes of marine and freshwater three-spined sticklebacks. 2646 36