... assubstrate in PCR with the following Ras-GRF1 gene-speci-fic primers: ON3 57, 5¢-TGAAACATCACCAACTAAATCTCCAA-3¢; ON3 58, 5¢-GACGACTCCATTGTTATAGGAAAAGAGT-3¢; ON3 59, 5 ¢-GCCGCTGGAGAAACAGCAT-3¢; ON3 60, ... cleared by centrifugation (13 000 g at 4 °C) and the protein concentrations in the supernatants were quanti-fied by the BC assay quantification kit (Uptima) using BSAas the standard. Equal amounts ... A, Greenberg ME & Feig LA (1995) Calcium activation of Ras mediated by neuronal exchange factor Ras-GRF.Nature 376, 524–527.11 Mattingly RR, Saini V & Macara IG (1999) Activation of the Ras-GRF...