Glomerulus proteome analysis with two-dimensional gel electrophoresis and mass spectrometry

A proteome analysis of mammalian glomeruli was performed in mouse using two-dimensional-gel electrophoresis with separate Coomassie and silver staining and subsequent mass spectrometric identifications. Altogether, 414 protein spots were identified, revealing 232 different proteins representing a wide spectrum of activities, including enzymes (27%), cell-signalling proteins (22%), structural proteins (12%), protein folding and metabolism (13%), cell-growth-related proteins (6%), and replication, transcription and translation (4%). Only 53 of the proteins were detected in another proteome study, showing the value of analyses with different methodologies. However, 50 of the proteins were also identified in a proteome analysis of endothelial cells and 42 in one of glomerular mesangial cells, revealing distinct similarities between these tissues, but also unique differences. Finally, 80 of the proteins were not identified in a separate transcriptome analysis, while 10 of the present proteins were then indentifiable with genes implicated in glomerulus development and function, allowing direct correlation with expression data.