title: Different conformational dynamics of β-arrestin1 and β-arrestin2 analyzed by hydrogen/deuterium exchange mass spectrometry.
abstract: Arrestins have important roles in G protein-coupled receptor (GPCR) signaling including desensitization of GPCRs and G protein-independent signaling. There have been four arrestins identified: arrestin1, arrestin2 (e.g. β-arrestin1), arrestin3 (e.g. β-arrestin2), and arrestin4. β-Arrestin1 and β-arrestin2 are ubiquitously expressed and regulate a broad range of GPCRs, while arrestin1 and arrestin4 are expressed in the visual system. Although the functions of β-arrestin1 and β-arrestin2 widely overlap, β-arrestin2 has broader receptor selectivity, and a few studies have suggested that β-arrestin1 and β-arrestin2 have distinct cellular functions. Here, we compared the conformational dynamics of β-arrestin1 and β-arrestin2 by hydrogen/deuterium exchange mass spectrometry (HDX-MS). We also used the R169E mutant as a pre-activation model system. HDX-MS data revealed that β-strands II through IV were more dynamic in β-arrestin2 in the basal state, while the middle loop was more dynamic in β-arrestin1. With pre-activation, both β-arrestin1 and β-arrestin2 became more flexible, but broader regions of β-arrestin1 became flexible compared to β-arrestin2. The conformational differences between β-arrestin1 and β-arrestin2 in both the basal and pre-activated states might determine their different receptor selectivities and different cellular functions.
authors.affiliation: School of Pharmacy, Sungkyunkwan University, Suwon, Republic of Korea.
authors.forename: Youngjoo
authors.initials: Y
authors.lastname: Yun
authors.affiliation: School of Pharmacy, Sungkyunkwan University, Suwon, Republic of Korea.
authors.forename: Dong Kyun
authors.initials: DK
authors.lastname: Kim
authors.affiliation: College of Pharmacy & Department of Molecular Science and Technology, Ajou University, Suwon, Republic of Korea.
authors.forename: Min-Duk
authors.initials: MD
authors.lastname: Seo
authors.affiliation: College of Pharmacy, Chonnam National University, Gwang-Ju, Republic of Korea.
authors.forename: Kyeong-Man
authors.initials: KM
authors.lastname: Kim
authors.affiliation: School of Pharmacy, Sungkyunkwan University, Suwon, Republic of Korea. Electronic address: kychung2@skku.edu.
authors.forename: Ka Young
authors.initials: KY
authors.lastname: Chung
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D019390:Arrestins / Q000737:chemistry*; D041961:Deuterium Exchange Measurement; D013058:Mass Spectrometry; D008969:Molecular Sequence Data; D050505:Mutant Proteins / Q000737:chemistry; D017433:Protein Structure, Secondary; D051381:Rats; D016415:Sequence Alignment; D000071557:beta-Arrestins
chemical_list: D019390:Arrestins; D050505:Mutant Proteins; D000071557:beta-Arrestins
keywords: Conformational dynamics; Hydrogen/deuterium exchange mass spectrometry; Pre-activation; β-Arrestin