New therapeutic strategies of GPCR diseases

2019 Fiscal Year Final Research Report

• Project/Area Number: 16K09797
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Endocrinology
• Research Institution: The University of Tokyo
• Principal Investigator: MAKITA Noriko 東京大学, 医学部附属病院, 准教授 (60353455)
• Co-Investigator(Kenkyū-buntansha): 間中 勝則 東京大学, 医学部附属病院, 助教 (10700495)
• Project Period (FY): 2016-04-01 – 2020-03-31
• Keywords: GPCR / biased agonism / protean agonism / endocrine disease

Outline of Final Research Achievements

Analysis of rare endocrine diseases caused by GPCR signaling disorder has revealed how GPCR signaling can be regulated specifically. In a patient diagnosed with acquired hypocalciuric hypercalcemia, we found unique autoantibodies working as biased allosteric modulators against CaSR and disclosed where they act. In vitro analysis, we found that cinacalcet can overcome the effect of the autoantibodies by working as a positive allosteric modulator and succeeded in treating the patient with cinacalcet. In cells expressing V2R mutants causing nephrogenic diabetes insipidus, including a novel one, we found that an agonist pharmacochaperone helps the mutants to be folded correctly and translocated to plasma membrane, and enables sustainable signaling, depending on the residual activity of each mutant (protean agonism). These results may help us to reveal the unique structure of GPCR which activates a specific signaling and to create a novel drug which activates only a desired signaling.

Free Research Field

内分泌学

Academic Significance and Societal Importance of the Research Achievements

Gタンパク質共役受容体（GPCR）に対するこれまでの薬剤は、GPCRシグナルを全体として刺激したり抑制することで、望ましくないシグナルを発生させたり、望ましいシグナルも抑えたりする問題があった。本研究成果は、望ましいシグナルのみをオンとできるGPCRのユニークな活性化構造の解明につながり、新たな創薬の基盤となる可能性がある。