PDZD11 (PDZ domain containing 11) functions as a critical adaptor protein that regulates membrane protein localization and cell junction organization. The protein primarily operates through its interaction with PLEKHA7 at adherens junctions, where PDZD11's N-terminal region binds to PLEKHA7's tandem WW domains in a cooperative manner 1. This PLEKHA7-PDZD11 complex serves multiple regulatory functions: it stabilizes nectins by preventing their proteasome-mediated degradation and promotes efficient early junction assembly 2, mediates ADAM10 clustering at cell-cell junctions by facilitating PLEKHA7's interaction with TSPAN33 3, and regulates calcium homeostasis by controlling PMCA localization and activity 4. PDZD11 also enhances the function of the sodium-dependent multivitamin transporter (hSMVT) in intestinal epithelial cells, increasing biotin uptake by promoting transporter membrane expression 5. The protein shows tissue-specific expression patterns and differential association with tight junction proteins depending on cell type 6. Through these diverse interactions, PDZD11 plays important roles in epithelial barrier function, calcium handling, and membrane protein trafficking, with potential clinical relevance in hypertension and cellular responses to bacterial toxins.