2013 Fiscal Year Final Research Report
Elucidating the function of GPCR dimerization by single-molecule observation
| Project/Area Number |
24770120
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| Research Category |
Grant-in-Aid for Young Scientists (B)
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| Allocation Type | Multi-year Fund |
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| Research Field |
Functional biochemistry
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| Research Institution | Kyoto University |
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Principal Investigator |
KASAI Rinshi 京都大学, 再生医科学研究所, 助教 (20447949)
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| Project Period (FY) |
2012-04-01 – 2014-03-31
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| Keywords | 生物物理 / 1分子計測 / Gタンパク質共役型受容体 / ダイマー形成 |
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| Research Abstract |
As a result of the single fluorescent molecule observation of beta 2 adrenergic receptor (b2AR), we found that 1) it's under the dynamic dimer-monomer equilibrium in the plasma membrane even at the resting state, 2) the dimer lifetime is ~80 milliseconds, 3) agonist stimulation increases the dimer lifetime by 40%. By observing trimeric G-protein together with b2AR at the single molecule level, it was further found that trimeric G-protein temporarily binds to b2AR monomers as well as dimers with comparable lifetimes, ~20 milliseconds. These reversible binding-unbinding processes were not affected by agonist stimulation. The results obtained here indicate that G-protein signaling is regulated in such a dynamic manner.
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