Protein unc-13 homolog B is a protein that in humans is encoded by the UNC13B gene. Function This gene is expressed in the kidney cortical epithelial cells and is upregulated by hyperglycemia. The encoded protein shares a high level of similarity to the rat homolog, and contains 3 C2 domains and a diacylglycerol-binding C1 domain. Hyperglycemia increases the levels of diacylglycerol, which has been shown to induce apoptosis in cells transfected with this gene and thus contribute to the renal cell complications of hyperglycemia. Studies in other species also indicate a role for this protein in the priming step of synaptic vesicle exocytosis. Interactions UNC13B has been shown to interact with: DOC2A, RIMS1, SPTBN2, STX1A, and STX1B. References Further reading