Low affinity of β 1 -adrenergic receptor for β-arrestins explains the resistance to agonist-induced internalization

Takako Shiina, Taku Nagao, Hitoshi Kurose

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12 Citations (Scopus)

Abstract

It has been reported that β-arrestin is essential for the internalization of many G protein-coupled receptors. Since β 1 -adrenergic receptor (β 1 AR) shows the resistance to agonist-induced internalization, we examine the interaction of β-arrestin with β 1 AR with three different approaches: translocation of β-arrestin to the plasma membrane, direct binding of in vitro translated β-arrestin to intracellular domains of β 1 - and β 2 ARs, inhibition of β 1 - and β 2 AR-stimulated adenylyl cyclase activities by β-arrestin. The enhanced green fluorescent protein (EGFP)-tagged β-arrestin 2 (β-arrestin 2-GFP) translocates to and stays at the plasma membrane by β 2 AR stimulation. β-Arrestin 2-GFP also translocates to the plasma membrane upon β 1 AR stimulation. However, it returns to the cytoplasm 10 - 30 min after agonist stimulation. The amount of β-arrestin bound to the third intracellular loop and the carboxyl tail of β 1 AR is lower than that of β 2 AR. The fusion protein of β-arrestin 1 with glutathione-S-transferase inhibits the β 1 - and β 2 AR-stimulated adenylyl cyclase activities. However, inhibition of the β 1 AR-stimulated activity requires a higher amount of the fusion protein than that of the β 2 AR-stimulated activity. These results suggest that affinity of β 1 AR for β-arrestins is lower than that of β 2 AR, and explains the resistance to agonist-induced internalization. This conclusion is further supported by the finding that β-arrestin can induce internalization of β 1 AR when β-arrestin 1 fused to the carboxyl tail of β 1 AR.

Original languageEnglish
Pages (from-to)2251-2257
Number of pages7
JournalLife Sciences
Volume68
Issue number19-20
DOIs
Publication statusPublished - Apr 6 2001
Externally publishedYes

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All Science Journal Classification (ASJC) codes

  • Biochemistry, Genetics and Molecular Biology(all)
  • Pharmacology, Toxicology and Pharmaceutics(all)

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