Journal article
Two human patient mitochondrial pyruvate carrier mutations reveal distinct molecular mechanisms of dysfunction
JCI insight, Vol.4(13), e126132
07/11/2019
DOI: 10.1172/jci.insight.126132
PMCID: PMC6629238
PMID: 31145700
Abstract
The mitochondrial pyruvate carrier (MPC) occupies a central metabolic node by transporting cytosolic pyruvate into the mitochondria! matrix and linking glycolysis with mitochondrial metabolism. Two reported human MPC1 mutations cause developmental abnormalities, neurological problems, metabolic deficits, and for one patient, early death. We aimed to understand biochemical mechanisms by which the human patient C289T and T236A MPC1 alleles disrupt MPC function. MPC1 C289T encodes 2 protein variants, a misspliced, truncation mutant (A58G) and a full-length point mutant (R97W). MPC1 T236A encodes a full-length point mutant (L79H). Using human patient fibroblasts and complementation of CRISPR-deleted, MPC1-null mouse C2C12 cells, we investigated how MPC1 mutations cause MPC deficiency. Truncated MPC1 A58G protein was intrinsically unstable and failed to form MPC complexes. The MPC1 R97W protein was less stable but, when overexpressed, formed complexes with MPC2 that retained pyruvate transport activity. Conversely, MPC1 L79H protein formed stable complexes with MPC2, but these complexes failed to transport pyruvate. These findings inform MPC structure-function relationships and delineate 3 distinct biochemical pathologies resulting from 2 human patient MPCI mutations. They also illustrate an efficient gene pass-through system for mechanistically investigating human inborn errors in pyruvate metabolism.
Details
- Title: Subtitle
- Two human patient mitochondrial pyruvate carrier mutations reveal distinct molecular mechanisms of dysfunction
- Creators
- Lalita Oonthonpan - Roy J. and Lucille A. Carver College of MedicineAdam J. Rauckhorst - Roy J. and Lucille A. Carver College of MedicineLawrence R. Gray - Roy J. and Lucille A. Carver College of MedicineAudrey C. Boutron - Assistance Publique – Hôpitaux de ParisEric B. Taylor - Roy J. and Lucille A. Carver College of Medicine
- Resource Type
- Journal article
- Publication Details
- JCI insight, Vol.4(13), e126132
- DOI
- 10.1172/jci.insight.126132
- PMID
- 31145700
- PMCID
- PMC6629238
- NLM abbreviation
- JCI Insight
- ISSN
- 2379-3708
- eISSN
- 2379-3708
- Publisher
- Amer Soc Clinical Investigation Inc
- Number of pages
- 14
- Grant note
- R01DK104998 / NATIONAL INSTITUTE OF DIABETES AND DIGESTIVE AND KIDNEY DISEASES; United States Department of Health & Human Services; National Institutes of Health (NIH) - USA; NIH National Institute of Diabetes & Digestive & Kidney Diseases (NIDDK) T32HL007638 / NATIONAL HEART, LUNG, AND BLOOD INSTITUTE; United States Department of Health & Human Services; National Institutes of Health (NIH) - USA; NIH National Heart Lung & Blood Institute (NHLBI) R01 DK104998; R00 AR059190; T32 HL007638; ADA 1-18-PDF-060; F32 DK101183; P30CA086862 / NIH; United States Department of Health & Human Services; National Institutes of Health (NIH) - USA P30CA086862 / NATIONAL CANCER INSTITUTE; United States Department of Health & Human Services; National Institutes of Health (NIH) - USA; NIH National Cancer Institute (NCI)
- Language
- English
- Date published
- 07/11/2019
- Academic Unit
- Molecular Physiology and Biophysics; Fraternal Order of Eagles Diabetes Research Center; Biochemistry and Molecular Biology
- Record Identifier
- 9984297509102771
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