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Miljkovic M, Seguin A, Jia X, Cox JE, Catrow JL, Bergonia H, Phillips JD, Stephens WZ, Ward DM. Loss of the mitochondrial protein Abcb10 results in altered arginine metabolism in MEL and K562 cells and nutrient stress signaling through ATF4. J Biol Chem 2023:104877. [PMID: 37269954 PMCID: PMC10316008 DOI: 10.1016/j.jbc.2023.104877] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2023] [Revised: 05/11/2023] [Accepted: 05/25/2023] [Indexed: 06/05/2023] Open
Abstract
Abcb10 is a mitochondrial membrane protein involved in hemoglobinization of red cells. Abcb10 topology and ATPase domain localization suggest it exports a substrate, likely biliverdin, out of mitochondria that is necessary for hemoglobinization. In this study we generated Abcb10 deletion cell lines in both mouse murine erythroleukemia (MEL) and human erythroid precursor human myelogenous leukemia (K562) cells to better understand the consequences of Abcb10 loss. Loss of Abcb10 resulted in an inability to hemoglobinize upon differentiation in both K562 and MEL cells with reduced heme and intermediate porphyrins and decreased levels of aminolevulinic acid synthase 2 activity. Metabolomic and transcriptional analyses revealed that Abcb10 loss gave rise to decreased cellular arginine levels, increased transcripts for cationic and neutral amino acid transporters with reduced levels of the citrulline to arginine converting enzymes argininosuccinate synthetase and argininosuccinate lyase. The reduced arginine levels in Abcb10 null cells gave rise to decreased proliferative capacity. Arginine supplementation improved both Abcb10 null proliferation and hemoglobinization upon differentiation. Abcb10 null cells showed increased phosphorylation of Eukaryotic Translation Initiation Factor 2 Subunit Alpha (eIF2A), increased expression of nutrient sensing transcription factor ATF4 and downstream targets DNA damage inducible transcript 3 (Chop), ChaC glutathione specific gamma-glutamylcyclotransferase 1 (Chac1) and arginyl-tRNA synthetase 1 (Rars). These results suggest that when the Abcb10 substrate is trapped in the mitochondria, the nutrient sensing machinery is turned on remodeling transcription to block protein synthesis necessary for proliferation and hemoglobin biosynthesis in erythroid models.
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Affiliation(s)
- Marisa Miljkovic
- Department of Pathology, Division of Microbiology and Immunology, Division of Hematology, University of Utah School of Medicine, Salt Lake City, UT 84132, USA
| | - Alexandra Seguin
- Department of Pathology, Division of Microbiology and Immunology, Division of Hematology, University of Utah School of Medicine, Salt Lake City, UT 84132, USA
| | - Xuan Jia
- Department of Pathology, Division of Microbiology and Immunology, Division of Hematology, University of Utah School of Medicine, Salt Lake City, UT 84132, USA
| | - James E Cox
- Department of Biochemistry, Division of Hematology, University of Utah School of Medicine, Salt Lake City, UT 84132, USA; Metabolomics Core Research Facility, Division of Hematology, University of Utah School of Medicine, Salt Lake City, UT 84132, USA
| | - Jonathan Leon Catrow
- Metabolomics Core Research Facility, Division of Hematology, University of Utah School of Medicine, Salt Lake City, UT 84132, USA
| | - Hector Bergonia
- Iron and Heme Core Research Facility, Division of Hematology, University of Utah School of Medicine, Salt Lake City, UT 84132, USA
| | - John D Phillips
- Department of Medicine, Division of Hematology, University of Utah School of Medicine, Salt Lake City, UT 84132, USA
| | - W Zac Stephens
- Department of Pathology, Division of Microbiology and Immunology, Division of Hematology, University of Utah School of Medicine, Salt Lake City, UT 84132, USA
| | - Diane M Ward
- Department of Pathology, Division of Microbiology and Immunology, Division of Hematology, University of Utah School of Medicine, Salt Lake City, UT 84132, USA.
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