Secretomics

Secretomics is a type of proteomics which involves the analysis of the secretome—all the secreted proteins of a cell, tissue or organism. Secreted proteins are involved in a variety of physiological processes, including cell signaling and matrix remodeling, but are also integral to invasion and metastasis of malignant cells. Secretomics has thus been especially important in the discovery of biomarkers for cancer and understanding molecular basis of pathogenesis. The analysis of the insoluble fraction of the secretome (the extracellular matrix) has been termed matrisomics.

==History of the secretome== In 2000 Tjalsma et al. coined the term 'secretome' in their study of the eubacterium B. subtilis. They defined the secretome as all of the secreted proteins and secretory machinery of the bacteria. Using a database of protein sequences in B. subtilis and an algorithm that looked at cleavage sites and amino-terminal signal peptides characteristic of secreted proteins they were able to predict what fraction of the proteome is secreted by the cell. In 2001 the same lab set a standard of secretomics – predictions based on amino acid sequence alone are not enough to define the secretome. They used two-dimensional gel electrophoresis and mass spectrometry to identify 82 proteins secreted by B. subtilis, only 48 of which had been predicted using the genome-based method of their previous paper. This demonstrates the need for protein verification of predicted findings.