GP73 regulates Hepatic Steatosis by enhancing SCAP-SREBPs interaction

Sci Rep. 2017 Nov 2;7(1):14932. doi: 10.1038/s41598-017-06500-9.

Abstract

Elevated Golgi phosphoprotein 2 (GP73, also known as GOLPH2 or GOLM1) expression in serum and liver, which can be induced by viral infection and cytokine treatments, is intimately connected with liver disease, including acute hepatitis, cirrhosis and hepatocellular carcinoma (HCC). However, its pathogenic roles in hepatic diseases have never been clarified in detail. Here, we showed that the upregulated GP73 is indispensable for SREBPs activation and lipogenesis. Notably, GP73 overexpression enhanced SCAP-SREBPs binding and its Golgi trafficking even under cholesterol sufficiency. Consistent with these functional findings, GP73 blockage could alleviate tunicamycin-induced liver steatosis by reducing SREBPs activation. A significant positive correlation of GP73 with genes in lipid metabolism pathway was also identified in liver cancer based on data from The Cancer Genome Atlas (TCGA) dataset. Our findings revealed previously unrecognized role of GP73 in lipid metabolism.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Fatty Liver / metabolism*
  • Fatty Liver / pathology
  • Golgi Apparatus / genetics
  • Golgi Apparatus / metabolism
  • Hep G2 Cells
  • Humans
  • Intracellular Signaling Peptides and Proteins / genetics
  • Intracellular Signaling Peptides and Proteins / metabolism*
  • Lipogenesis*
  • Liver Neoplasms / genetics
  • Liver Neoplasms / metabolism
  • Membrane Proteins / genetics
  • Membrane Proteins / metabolism*
  • Mice, Inbred C57BL
  • Phosphoproteins / genetics
  • Phosphoproteins / metabolism
  • Protein Interaction Maps*
  • Protein Transport
  • Sterol Regulatory Element Binding Protein 1 / genetics
  • Sterol Regulatory Element Binding Protein 1 / metabolism*
  • Transcriptional Activation
  • Up-Regulation

Substances

  • GOLM1 protein, human
  • GP73 protein, mouse
  • Intracellular Signaling Peptides and Proteins
  • Membrane Proteins
  • Phosphoproteins
  • SREBF1 protein, human
  • SREBP cleavage-activating protein
  • Sterol Regulatory Element Binding Protein 1