Riboflavin transporter SLC52A1, a target of p53, suppresses cellular senescence by activating mitochondrial complex II

Mol Biol Cell. 2021 Nov 1;32(21):br10. doi: 10.1091/mbc.E21-05-0262. Epub 2021 Sep 15.

Abstract

Cellular senescence is a state of permanent proliferative arrest induced by a variety of stresses, such as DNA damage. The transcriptional activity of p53 has been known to be essential for senescence induction. It remains unknown, however, whether among the downstream genes of p53, there is a gene that has antisenescence function. Our recent studies have indicated that the expression of SLC52A1 (also known as GPR172B/RFVT1), a riboflavin transporter, is up-regulated specifically in senescent cells depending on p53, but the relationship between senescence and SLC52A1 or riboflavin has not been described. Here, we examined the role of SLC52A1 in senescence. We found that knockdown of SLC52A1 promoted senescence phenotypes induced by DNA damage in tumor and normal cells. The senescence suppressive action of SLC52A1 was dependent on its riboflavin transport activity. Furthermore, elevation of intracellular riboflavin led to activation of mitochondrial membrane potential (MMP) mediated by the mitochondrial electron transport chain complex II. Finally, the SLC52A1-dependent activation of MMP inhibited the AMPK-p53 pathway, a central mediator of mitochondria dysfunction-related senescence. These results suggest that SLC52A1 contributes to suppress senescence through the uptake of riboflavin and acts downstream of p53 as a negative feedback mechanism to limit aberrant senescence induction.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cell Line, Tumor
  • Cellular Senescence / physiology*
  • Electron Transport Complex II / metabolism
  • Humans
  • Membrane Potential, Mitochondrial / physiology
  • Membrane Transport Proteins / metabolism
  • Mitochondria / metabolism
  • Mitochondrial Membranes / metabolism
  • Receptors, G-Protein-Coupled / metabolism*
  • Receptors, G-Protein-Coupled / physiology*
  • Riboflavin / metabolism
  • Signal Transduction / physiology
  • Tumor Suppressor Protein p53 / metabolism

Substances

  • Membrane Transport Proteins
  • Receptors, G-Protein-Coupled
  • SLC52A1 protein, human
  • Tumor Suppressor Protein p53
  • Electron Transport Complex II
  • Riboflavin