THE 2 ISOFORMS OF THE MOUSE SOMATOSTATIN RECEPTOR (MSSTR2A AND MSSTR2B) DIFFER IN COUPLING EFFICIENCY TO ADENYLATE-CYCLASE AND IN AGONIST-INDUCED RECEPTOR DESENSITIZATION

The somatostatin receptor 2 (mSSTR2) is alternatively spliced into two isoforms (mSSTR2A and mSSTR2B) which differ at the C-terminus. Both receptors bind somatostatin peptides with a similar high affinity when stably expressed in CHO-K1 cells. However, the spliced form (mSSTR2B) mediates a more efficient inhibition of adenylate cyclase and is much more resistant to agonist-induced reduction of binding than the longer form (mSSTR2A). These findings indicate that alternative splicing may be a physiological mechanism to modulate receptor desensitization and G-protein coupling of mSSTR2.