Quantitative mass spectrometry-based proteomics reveals the dynamic range of primary mouse astrocyte protein secretion

J Proteome Res. 2010 May 7;9(5):2764-74. doi: 10.1021/pr100134n.


Growing appreciation for astrocytes as active participants in nervous system development, neurovascular metabolic coupling, and neurological disease progression has stimulated recent investigation into specific astrocyte-secreted proteins that may mediate these functions. The current work utilized SILAC-generated isotope reference proteomes to quantify relative protein abundances between the astrocyte proteome and secretome. Multidimensional GeLC-MS/MS analysis of astrocyte conditioned media and cell lysates resulted in the relative quantification of 516 proteins, 92 of which were greater than 1.5-fold enriched in astrocyte-conditioned media (ACM). Eighty of the ACM-enriched proteins had N-terminal signal peptides, comprising well-known classically secreted proteins, such as apolipoprotein E and SPARC, and several cathepsins that localize to endosomal/lysosomal compartments. The remaining twelve ACM-enriched proteins, such as vimentin, ferritins, and histones, lacked N-terminal signal peptides. Also, 47 proteins contained predicted N-terminal signal peptides but were not enriched in ACM (<1.5-fold), 25 of which were localized to ER, Golgi, or mitochondria membrane-bound compartments. Overall, by combining quantitative proteomics with subcellular localization prediction, an informative description of protein distribution can be obtained, providing insights into protein secretion.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Astrocytes / metabolism*
  • Blotting, Western
  • Brefeldin A / pharmacology
  • Cells, Cultured
  • Chromatography, Gel
  • Culture Media, Conditioned / pharmacology
  • Isotope Labeling / methods*
  • Least-Squares Analysis
  • Mice
  • Proteins / analysis
  • Proteins / metabolism*
  • Proteome / analysis
  • Proteome / drug effects
  • Proteome / metabolism*
  • Proteomics / methods*
  • Reproducibility of Results
  • Tandem Mass Spectrometry / methods*


  • Culture Media, Conditioned
  • Proteins
  • Proteome
  • Brefeldin A