Figure 2. Protein annotation using UniProtKB/Swiss-Prot, EBI and UniProtKB/TrEMBL databases.

A. Annotation of identified parotid exosome integral plasma membrane proteins by function. Twenty-two % of the proteins identified were receptors and the minority (2%) was represented by pumps and/or calcium binding/ion transport proteins. B. Annotation of identified parotid exosome peripheral membrane proteins by function. The bulk of parotid exosomal proteins was associated with proteins involved in signaling pathways, while lesser amounts of proteins were linked to ion binding/transport and actin binding activities. C. Annotation of identified parotid exosome cytosolic proteins by function. Thirty-four % of the cytosolic proteins were associated with catalytic activities whilst only 0.5% with protease inhibitor activity.