Argonaute2 regulates the pancreatic β-cell secretome

Mol Cell Proteomics. 2013 May;12(5):1214-25. doi: 10.1074/mcp.M112.024786. Epub 2013 Jan 28.

Abstract

Argonaute2 (Ago2) is an established component of the microRNA-induced silencing complex. Similar to miR-375 loss-of-function studies, inhibition of Ago2 in the pancreatic β-cell resulted in enhanced insulin release underlining the relationship between these two genes. Moreover, as the most abundant microRNA in pancreatic endocrine cells, miR-375 was also observed to be enriched in Ago2-associated complexes. Both Ago2 and miR-375 regulate the pancreatic β-cell secretome, and by using quantitative mass spectrometry, we identified the enhanced release of a set of proteins or secretion "signatures " in response to a glucose stimulus using the murine β-cell line MIN6. In addition, the loss of Ago2 resulted in the increased expression of miR-375 target genes, including gephyrin and ywhaz. These targets positively contribute to exocytosis indicating they may mediate the functional role of both miR-375 and Ago proteins in the pancreatic β-cell by influencing the secretory pathway. This study specifically addresses the role of Ago2 in the systemic release of proteins from β-cells and highlights the contribution of the microRNA pathway to the function of this cell type.

MeSH terms

  • Animals
  • Argonaute Proteins / physiology*
  • Cell Line
  • Gene Expression Regulation
  • Insulin / metabolism
  • Insulin Secretion
  • Insulin-Secreting Cells / metabolism*
  • Mice
  • Mice, Inbred C57BL
  • MicroRNAs / metabolism
  • Proteome / genetics
  • Proteome / metabolism*
  • RNA Interference

Substances

  • Ago2 protein, mouse
  • Argonaute Proteins
  • Insulin
  • MicroRNAs
  • Mirn375 microRNA, mouse
  • Proteome