H2 relaxin-induced cAMP response of SLGYFP-RXFP1-LB2, NITK-RXFP1-LB2, LLH-RXFP1-LB2, and NGVD-RXFP1-LB2 (A) and SLGYFP-RXFP1-LB2, NITK-RXFP1-LB2, SLGYFP NITK-RXFP1-LB2, and SLGYFP NITK C-term-RXFP1-LB2 (B) compared with RXFP1. cAMP activity is expressed as the percentage of the 5 μm forskolin-stimulated response for each receptor and has been normalized for cell surface expression. Symbols represent means and vertical bars (not visible) represent S.E. of triplicate determinations from at least three independent experiments.