G Protein Coupled Receptor 78 (GPR78)

The response depended upon the cell line studied. UV-B was a weaker inducer, and UV-C and several other DNA-damaging agents did not induce GPR78 expression. Induction of GPR78 by tunicamycin required activation of multiple ER stress-response elements in the promoter of the GPR78 gene, and induction by a DNA-alkylating agent was independent of the unfolded protein response.GPR78 encodes a deduced 363-amino acid protein that shares 56% sequence identity with GPR26 in the transmembrane region. Northern blot analysis revealed a 1.1-kb transcript in pituitary, and 1.1- and 4.2-kb transcripts in placenta. No expression was detected in brain, skeletal muscle, lung, heart, liver, pancreas, or kidney.