Syndecan-binding protein 1 (SDCBP) PDZ1 domain (SDCBP PDZ1)

The Syndecan-binding protein 1 (SDCBP) PDZ1 domain is a key structural motif within the scaffold protein Syntenin-1, also known as Melanoma Differentiation-Associated protein 9 (MDA-9) [1, 2]. It serves as a critical docking site for various transmembrane receptors and signaling proteins, including Syndecans, IGF-1R, and EGFR, thereby facilitating the assembly of complexes essential for exosome biogenesis and signal transduction [1, 4]. In oncogenic contexts, the PDZ1 domain is frequently overexpressed, driving tumor progression, invasion, and metastasis by activating downstream pathways such as STAT3, Src, and NF-kappaB [1, 3]. Small molecule inhibitors like PDZ1i (113B7) have been developed to specifically target this domain, disrupting these protein-protein interactions and demonstrating significant anti-tumor activity in preclinical models of prostate cancer and glioblastoma [1, 5]. Because SDCBP knockout mice are viable and show no major physiological defects, targeting the PDZ1 domain is considered a promising and potentially safe strategy for inhibiting cancer metastasis [1, 2]. This domain's role as a molecular "nexus" makes it a focal point for therapeutic intervention in aggressive, metastatic cancers [2, 3]. Furthermore, its involvement in exosome cargo sorting suggests that inhibiting this domain could also modulate the tumor microenvironment by altering intercellular communication [4, 5].

Other names

Syntenin-1 PDZ1 domainMDA-9 PDZ1 domainMelanoma differentiation-associated protein 9 PDZ1 domainPro-TGF-alpha cytoplasmic domain-interacting protein PDZ1 domain

Inhibition of protein-protein interactions (PPIs) between the PDZ1 domain and its ligands (such as IGF-1R, EGFR, and TGF-beta), thereby disrupting downstream oncogenic signaling pathways including STAT3, Src, and NF-kappaB [1, 3].