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A Scalable, Cell-Based Method for the Functional Assessment of Ube3a Variants
Published on: October 10, 2022
Identification and characterization of a novel ABCA3 mutation
Sang-Kyu Park1, Louella Amos, Aparna Rao
1Department of Pediatrics, Medical College of Wisconsin, Milwaukee, Wisconsin 53201, USA.
Physiological Genomics
|October 29, 2009
Summary
A novel ATP-binding cassette protein A3 (ABCA3) mutation (R295C) causes reduced ATP hydrolysis, potentially leading to severe respiratory issues in premature infants with ABCA3 haploinsufficiency.
Area of Science:
- Genetics
- Pulmonology
- Biochemistry
Background:
- Mutations in the ATP-binding cassette protein A3 (ABCA3) gene are linked to various lung diseases.
- Known ABCA3 mutations often impair protein localization or ATP hydrolysis.
- ABCA3 is crucial for lung surfactant homeostasis.
Purpose of the Study:
- To characterize a novel heterozygous ABCA3 mutation (R295C) found in a premature infant with respiratory insufficiency.
- To investigate the functional impact of the R295C mutation on ABCA3 protein activity.
Main Methods:
- Generated plasmid vectors for wild-type and R295C mutant ABCA3 tagged with green fluorescent protein.
- Assessed protein glycosylation and intracellular localization in transiently transfected HEK293 cells.
- Measured ATP hydrolysis activity using a vanadate-induced nucleotide trapping assay in stably transfected HEK293 cells.
Main Results:
- The R295C mutant ABCA3 protein exhibited normal glycosylation and cellular localization.
- ATP hydrolysis activity of the R295C mutant was significantly reduced, retaining only 12% of wild-type function.
- The identified mutation was confirmed as novel and not a common variant.
Conclusions:
- The R295C mutation impairs ABCA3 function by drastically reducing ATP hydrolysis.
- ABCA3 haploinsufficiency, particularly in premature lungs, may contribute to severe or prolonged respiratory failure.
- This finding highlights the importance of ABCA3 function in neonatal lung health.
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