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. 2023 Mar 9;13(3):502. doi: 10.3390/biom13030502

Figure 1.

Figure 1

Representation of osteopontin gene, protein structure, and receptor binding. (A) Human OPN-encoding gene (SPP1) is located on the chromosome 4q21-25 and gives five messenger RNA, where OPN-a is the version with coding information from all exons. (B) OPN full-length (OPN-FL) is a 314 amino acid glycosylated phosphoprotein that contains the Arg-Gly-Asp (RGD) motif sequence, SVVYGLR domain, thrombin cleavage sequence, heparan sulfate binding domain, and heparin/CD44 binding domain. (C) OPN is heavily posttranslationally modified by serine/threonine phosphorylation, O-glycosylation, and tyrosine sulfation. (D) Thrombin cleavage changes the OPN conforming N-terminal fragment (OPN N-half), which allows access to the RGD motif. (E) OPN N-half interacts with integrins αvβ1 and αvβ3 to exert physiological and pathological functions. (F) OPN interaction with CD44 occurs through its putative binding domain located in the last 18 amino acids at the highly conserved C terminus. Created by Biorender with the CT24XI5TS7 agreement number.