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A novel system that reports the G‐proteins linked to a given receptor: a study of type 3 somatostatin receptor
Author(s) -
Komatsuzaki Katsumi,
Murayama Yoshitake,
Giambarella Ugo,
Ogata Etsuro,
Seino Susumu,
Nishimoto Ikuo
Publication year - 1997
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/s0014-5793(97)00257-3
Subject(s) - somatostatin receptor , somatostatin receptor 3 , somatostatin receptor 2 , somatostatin receptor 1 , receptor , somatostatin , chemistry , biochemistry , medicine , endocrinology , biology
SSTR3, a somatostatin (SST) receptor, is an adenylyl cyclase (AC)‐inhibiting receptor. To assign the G‐protein α‐subunit (Gα) linked to this receptor, we created a novel reporter system which utilizes the well‐established facts that the C‐terminal 5 residues of Gα are the receptor contact site and Gα s stimulates all subtypes of AC. We constructed chimeric Gα s the C‐terminal 5 residues of which were replaced with the corresponding C‐terminus of each known Gα, and examined which chimera confers SSTR3‐induced activation of AC. Cellular transfection of SSTR3 and measurement of SST‐dependent AC activity through co‐transfected chimeric Gα s revealed that SSTR3 recognizes the C‐termini of Gα i1/2 but not of Gα o or Gα z , and those of Gα 14 and Gα 16 , but not of Gα q or Gα 11 . As predicted by the chimeric Gα s , SST‐bound SSTR3 stimulated polyphosphoinositide turnover only when Gα 16 or Gα 14 was co‐transfected. We conclude that the chimeric Gα s system provides a new approach towards the assignment of G‐proteins linked to a given receptor.