Fig. 3

Protein-protein interaction networks of upregulated proteins associated with primary Sjögren’s syndrome detected in extracellular vesicles from whole saliva. One major protein-protein interaction network is visualised. The proteins identified are involved in the cytoskeleton, in addition to cell migration and cell junction. Out of the five most upregulated proteins in pSS (Table 4), indicated with red circles, both guanine nucleotide-binding protein subunit alpha-13 (GNA13) and WD repeat-containing protein 1 (WDR1) are present within this protein network. The Search Tool for the Retrieval of Interacting Genes/Proteins (http://string-db.org/) was used to generate the networks, where potential interactions of proteins with medium confidence are shown. The different clusters are indicated by the same colour. The colour of the connecting lines indicates the type of evidence used in predicting the associations (red gene fusion, yellow text-mining extracted from literature, purple protein-protein interaction datasets, light blue protein interaction groups, black linked across species). APMAP membrane-associated protein, SIRPA tyrosine-protein phosphatase non-receptor type substrate 1, LSP1 lymphocyte-specific protein 1