Osteopontin Bridging Innate and Adaptive Immunity in Autoimmune Diseases

Figure 1

Genomic, transcriptional, and protein features of OPN. The figure shows in the upper panel the genomic organization of the SPP1 gene and the relevant single nucleotide polymorphisms. OPN is transcribed with 3 splicing variants: variant a contains exons 2–7 while variants b and c lack exons 5 and 4, respectively (middle panel). OPN transcripts have also two starting points generating a secreted or/and intracellular form. Several posttranslational modifications are also shown (lower panel) including phosphorylation (asterisks), glycosylation, and sulfation sites. Proteases (thrombin and matrix metalloproteinase, MMP) cleavage sites are also depicted.