An 8% SDS-PAGE with Tricine buffer system was used to separate proteins. Completed gels were dried on a Bio-Rad gel dryer. The gels were then exposed to a storage phosphor screen for 5 days, and the autoradiograms were acquired using a Cyclone PhosphorImager (PerkinElmer Life Sciences). The intensities of radioactive bands were analyzed with the OptiQuant program (PerkinElmer Life Sciences), with local background subtracted from each lane.
