Deficit of human ornithine aminotransferase in gyrate atrophy: Molecular, cellular, and clinical aspects.

Abstract

Gyrate Atrophy (GA) of the choroid and retina (MIM# 258870) is an autosomal recessive disorder due to mutations of the OAT gene encoding ornithine-delta-aminotransferase (OAT), associated with progressive retinal deterioration and blindness. The disease has a theoretical global incidence of approximately 1:1,500,000. OAT is mainly involved in ornithine catabolism in adults, thus explaining the hyperornithinemia as hallmark of the disease. Patients are treated with an arginine-restricted diet, to limit ornithine load, or the administration of Vitamin B6, a precursor of the OAT coenzyme pyridoxal phosphate. Although the clinical and genetic aspects of GA are known for many years, the enzymatic phenotype of pathogenic variants and their response to Vitamin B6, as well as the molecular mechanisms explaining retinal damage, are poorly clarified. Herein, we provide an overview of the current knowledge on the biochemical properties of human OAT and on the molecular, cellular, and clinical aspects of GA.

• Authors: Riccardo Montioli, Ilaria Bellezza, Maria Andrea Desbats, Carla Borri Voltattorni, Leonardo Salviati, Barbara Cellini
• Journal: Biochimica et biophysica acta. Proteins and proteomics (Biochim Biophys Acta Proteins Proteom) Vol. 1869 Issue 1 Pg. 140555 (01 2021) ISSN: 1878-1454 [Electronic] Netherlands
• PMID: 33068755 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't, Review)
• Copyright: Copyright © 2020 Elsevier B.V. All rights reserved.

Chemical References

• Coenzymes
• Pyridoxal Phosphate
• Vitamin B 6
• Arginine
• Ornithine
• OAT protein, human
• Ornithine-Oxo-Acid Transaminase

Topics

• Arginine (metabolism)
• Choroid (enzymology, pathology)
• Chromosomes, Human, Pair 10
• Coenzymes (administration & dosage)
• Diet (methods)
• Gene Expression
• Gyrate Atrophy (diet therapy, enzymology, genetics, pathology)
• Humans
• Models, Molecular
• Mutation
• Ornithine (metabolism)
• Ornithine-Oxo-Acid Transaminase (chemistry, deficiency, genetics)
• Protein Multimerization
• Protein Structure, Secondary
• Pyridoxal Phosphate (administration & dosage)
• Retina (enzymology, pathology)
• Vitamin B 6 (administration & dosage)