Fig. 2. KiSS-1 and KiSS-1R are differentially expressed in FT and term human trophoblast cells. (A) RT-PCR of total RNA of freshly isolated FT or term trophoblasts (representative experiment: left panel). (B) Western blotting of FT and term trophoblasts. Lysates were probed with anti-Kp145/Kp-54 antiserum. With purified Kp-54 (5 ng) the antiserum produced a single band at 5-6 kDa, which is in good agreement with the theoretical MW for Kp-54 (5858.0 kDa; lane `M'). The antibody reacted only with lysates from FT trophoblasts producing one prominent band at 15-16 kDa, which is in good agreement with the calculated M_r for Kp-145 (15.391 kDa). ß-actin served as loading control. (C) FT trophoblast conditioned media were subjected to MALDI-TOF analysis after reverse phase-HPLC fractionation. The theoretical masses for C-terminally amidated Kps-10, -13, -14 and -54 are 1304, 1626, 1704 and 5858, respectively. Kp-54 was identified also as Na-adduct (m/z: 5876). The masses at around 2600 are unidentified.