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Assessment of Glutamine as a Fuel Source for Alveolar Macrophages Exposed to Chronic Ethanol Using an Extracellular Flux Bioanalyzer
Published on: November 15, 2024
321
Mitochondrial Raf1 Regulates Glutamine Catabolism.
Ronald L Shanderson1,2, Ian D Ferguson1,2, Zurab Siprashvili2
1Program in Cancer Biology, Stanford University, Stanford, CA, 94305, USA.
Biorxiv : the Preprint Server for Biology
|March 18, 2024
Summary
Raf1 kinase is found inside mitochondria, where it interacts with glutaminase (GLS) to support cancer cell growth by enabling glutamine metabolism. This non-canonical function impacts tumorigenesis independently of traditional signaling pathways.
Area of Science:
- Cell Biology
- Cancer Biology
- Biochemistry
Background:
- Raf kinases are crucial in cell signaling and cancer.
- The complete cellular localization and function of Raf-proximal proteins, particularly Raf1, remain incompletely understood.
- Understanding novel roles of Raf1 is key to cancer therapy.
Approach:
- Utilized Raf1 proximity proteomics (BioID) in cancer cells to identify Raf1-interacting proteins.
- Confirmed mitochondrial localization of Raf1 using mitochondrial purification and super-resolution microscopy.
- Investigated the functional interaction between mitochondrial Raf1 and glutaminase (GLS) in cancer cells and in vivo.
Key Points:
- Raf1 was unexpectedly found to localize within the mitochondrial matrix.
- Mitochondrial Raf1 directly interacts with glutaminase (GLS).
- This interaction promotes glutaminolysis, a vital process for cancer cell biosynthesis and survival.
- Raf1's role in mitochondria is independent of canonical MAP kinase signaling and requires its kinase activity.
Conclusions:
- Raf1 has a non-canonical role within the mitochondria.
- Mitochondrial Raf1-GLS interaction fuels cancer metabolism and tumorigenesis.
- Targeting mitochondrial Raf1 could offer new therapeutic strategies for cancer.
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