Leptin Receptor Gene Related Protein (OBRGRP)

OBRGRP and OBR share the same 5-prime UTR, but the initiating AUG codon for OBRGRP is upstream of that used by OBR, and OBRGRP is read in a different reading frame. The deduced 131-amino acid OBRGRP protein has a calculated molecular mass of 14.3 kD. Northern blot analysis detected OBRGRP transcripts of 1.3 to 2.4 kb in all 8 human tissues examined, with highest expression in heart and placenta. Obrgrp negatively regulated leptin signaling. Silencing of Obrgrp in the hypothalamic arcuate nucleus also prevented the development of high-fat diet-induced obesity. Coimmunoprecipitation analysis of cotransfected HeLa cells showed that Obrgrp interacted directly with Obr, and silencing of endogenous HeLa cell OBRGRP increased the cell surface expression of OBR.