Fig. 1.

Schematic of YHR and its signaling properties. (A) YHR consists of hCGβ with its signal sequence linked to human α-subunit through the C-terminal peptide (CTP) of hCGβ. This yoked hormone, in turn, is covalently attached to the extracellular domain of rLHR via an additional CTP and a factor Xa cleavage sequence. Constitutive activation of YHR and the D556H LHR mutant showing increases in basal cAMP (B) and IP (C) in HEK 293 cells in the absence and presence of additional hCG. The data are presented as fold-increase over LHR in the absence of exogenous hCG.