Haploid genetic screens identify SPRING/C12ORF49 as a determinant of SREBP signaling and cholesterol metabolism

Nat Commun. 2020 Feb 28;11(1):1128. doi: 10.1038/s41467-020-14811-1.

Abstract

The sterol-regulatory element binding proteins (SREBP) are central transcriptional regulators of lipid metabolism. Using haploid genetic screens we identify the SREBP Regulating Gene (SPRING/C12ORF49) as a determinant of the SREBP pathway. SPRING is a glycosylated Golgi-resident membrane protein and its ablation in Hap1 cells, Hepa1-6 hepatoma cells, and primary murine hepatocytes reduces SREBP signaling. In mice, Spring deletion is embryonic lethal yet silencing of hepatic Spring expression also attenuates the SREBP response. Mechanistically, attenuated SREBP signaling in SPRINGKO cells results from reduced SREBP cleavage-activating protein (SCAP) and its mislocalization to the Golgi irrespective of the cellular sterol status. Consistent with limited functional SCAP in SPRINGKO cells, reintroducing SCAP restores SREBP-dependent signaling and function. Moreover, in line with the role of SREBP in tumor growth, a wide range of tumor cell lines display dependency on SPRING expression. In conclusion, we identify SPRING as a previously unrecognized modulator of SREBP signaling.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cell Line
  • Cholesterol / metabolism*
  • Embryonic Development / genetics
  • Endoplasmic Reticulum / metabolism
  • Gene Expression
  • Golgi Apparatus / metabolism
  • Haploidy
  • Hepatocytes / metabolism
  • Humans
  • Intracellular Signaling Peptides and Proteins / genetics
  • Intracellular Signaling Peptides and Proteins / metabolism
  • Lipid Metabolism / genetics
  • Liver / metabolism
  • Membrane Glycoproteins / genetics
  • Membrane Glycoproteins / metabolism*
  • Membrane Proteins / genetics
  • Membrane Proteins / metabolism*
  • Mice
  • Mice, Inbred C57BL
  • Signal Transduction*
  • Sterol Regulatory Element Binding Proteins / genetics
  • Sterol Regulatory Element Binding Proteins / metabolism*

Substances

  • Intracellular Signaling Peptides and Proteins
  • Membrane Glycoproteins
  • Membrane Proteins
  • SPRING1 protein, human
  • SREBP cleavage-activating protein
  • Sterol Regulatory Element Binding Proteins
  • Cholesterol