한빛사논문
- 조회485
University of Washington, Southern University of Science and Technology
Seung-Ryoung Junga,b,c,1, Yifei Jiangb, Jong Bae Seod,e, Daniel T. Chiub,f, Bertil Hillea, and Duk-Su Koha
aDepartment of Physiology and Biophysics, University of Washington, Seattle, WA 98195; bDepartment of Chemistry, University of Washington, Seattle, WA 98195; cDepartment of Biomedical Engineering, Southern University of Science and Technology, Shenzhen, Guangdong 518055, China; dDepartment of Biosciences, Mokpo National University, Jeonnam 58554, Republic of Korea; eDepartment of Biomedicine, Health and Life Convergence Sciences, Mokpo National University, Jeonnam 58554, Republic of Korea; and fDepartment of Bioengineering, University of Washington, Seattle, WA 98195
1To whom correspondence may be addressed.
Abstract
β-arrestins regulate many cellular functions including intracellular signaling and desensitization of G protein–coupled receptors (GPCRs). Previous studies show that β-arrestin signaling and receptor endocytosis are modulated by the plasma membrane phosphoinositide lipid phosphatidylinositol-(4, 5)-bisphosphate (PI(4,5)P2). We found that β-arrestin also helped promote synthesis of PI(4,5)P2 and up-regulated GPCR endocytosis. We studied these questions with the Gq-coupled protease-activated receptor 2 (PAR2), which activates phospholipase C, desensitizes quickly, and undergoes extensive endocytosis. Phosphoinositides were monitored and controlled in live cells using lipid-specific fluorescent probes and genetic tools. Applying PAR2 agonist initiated depletion of PI(4,5)P2, which then recovered during rapid receptor desensitization, giving way to endocytosis. This endocytosis could be reduced by various manipulations that depleted phosphoinositides again right after phosphoinositide recovery: PI(4)P, a precusor of PI(4,5)P2, could be depleted at either the Golgi or the plasma membrane (PM) using a recruitable lipid 4-phosphatase enzyme and PI(4,5)P2 could be depleted at the PM using a recruitable 5-phosphatase. Endocytosis required the phosphoinositides. Knock-down of β-arrestin revealed that endogenous β-arrestin normally doubles the rate of PIP5-kinase (PIP5K) after PAR2 desensitization, boosting PI(4,5)P2-dependent formation of clathrin-coated pits (CCPs) at the PM. Desensitized PAR2 receptors were swiftly immobilized when they encountered CCPs, showing a dwell time of ∼90 s, 100 times longer than for unactivated receptors. PAR2/β-arrestin complexes eventually accumulated around the edges or across the surface of CCPs promoting transient binding of PIP5K-Iγ. Taken together, β-arrestins can coordinate potentiation of PIP5K activity at CCPs to induce local PI(4,5)P2 generation that promotes recruitment of PI(4,5)P2-dependent endocytic machinery.
β, phosphoinositide lipids, GPCR, endocytosis, PIP5K
논문정보
- Research article
- 2021년 04월 (BRIC 등록일 2021-04-30)
- 국내+국외 연구진
- 생명과학 > 구조생물 및 생물물리학
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