| Autor: |
Qu C; Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Peking University, Beijing 100191, China.; Key Laboratory of Molecular Cardiovascular Science, Ministry of Education, Beijing 100191, China.; Key Laboratory Experimental Teratology of the Ministry of Education and Department of Biochemistry and Molecular Biology, Shandong University School of Medicine, Jinan 250012, China., Park JY; School of Pharmacy, Sungkyunkwan University, Suwon 16419, Republic of Korea., Yun MW; School of Pharmacy, Sungkyunkwan University, Suwon 16419, Republic of Korea., He QT; Key Laboratory Experimental Teratology of the Ministry of Education and Department of Biochemistry and Molecular Biology, Shandong University School of Medicine, Jinan 250012, China., Yang F; Key Laboratory Experimental Teratology of the Ministry of Education, Department of Physiology, School of Basic Medical Sciences, Shandong University, Jinan 250012, China., Kim K; School of Pharmacy, Sungkyunkwan University, Suwon 16419, Republic of Korea., Ham D; School of Pharmacy, Sungkyunkwan University, Suwon 16419, Republic of Korea., Li RR; Key Laboratory Experimental Teratology of the Ministry of Education and Department of Biochemistry and Molecular Biology, Shandong University School of Medicine, Jinan 250012, China., Iverson TM; Department of Pharmacology, Vanderbilt University, Nashville, TN 37232., Gurevich VV; Department of Pharmacology, Vanderbilt University, Nashville, TN 37232., Sun JP; Key Laboratory Experimental Teratology of the Ministry of Education and Department of Biochemistry and Molecular Biology, Shandong University School of Medicine, Jinan 250012, China; kychung2@skku.edu sunjinpeng@sdu.edu.cn., Chung KY; School of Pharmacy, Sungkyunkwan University, Suwon 16419, Republic of Korea; kychung2@skku.edu sunjinpeng@sdu.edu.cn. |
| Abstrakt: |
Arrestins were initially identified for their role in homologous desensitization and internalization of G protein-coupled receptors. Receptor-bound arrestins also initiate signaling by interacting with other signaling proteins. Arrestins scaffold MAPK signaling cascades, MAPK kinase kinase (MAP3K), MAPK kinase (MAP2K), and MAPK. In particular, arrestins facilitate ERK1/2 activation by scaffolding ERK1/2 (MAPK), MEK1 (MAP2K), and Raf (MAPK3). However, the structural mechanism underlying this scaffolding remains unknown. Here, we investigated the mechanism of arrestin-2 scaffolding of cRaf, MEK1, and ERK2 using hydrogen/deuterium exchange-mass spectrometry, tryptophan-induced bimane fluorescence quenching, and NMR. We found that basal and active arrestin-2 interacted with cRaf, while only active arrestin-2 interacted with MEK1 and ERK2. The ATP binding status of MEK1 or ERK2 affected arrestin-2 binding; ATP-bound MEK1 interacted with arrestin-2, whereas only empty ERK2 bound arrestin-2. Analysis of the binding interfaces suggested that the relative positions of cRaf, MEK1, and ERK2 on arrestin-2 likely facilitate sequential phosphorylation in the signal transduction cascade. |
