... terminus of the CRFR1 isoforms (Fig 1C) The predicted masses of the isoforms without/with V5 tag are as follows: CRFR1a (47.7/52 kDa), CRFR1e1 (10.8/ 15.1 kDa), CRFR1e2 (28.1/32.4 kDa), CRFR1f ... CRFR1 a, b, c and d isoforms differ in their ability to bind ligands and activate G proteins [10,16,25] CRFR1a is the most efficient in the stimulation of cAMP production, CRFR1c and CRFR1b have ... independent of cAMP and IP3 [11,12,33] Neither CRFR1f, g or h isoforms were able to stimulate any of the cis-elements Instead the reporter gene expression decreased when these isoforms were cotransfected...