Homo- and hetero-oligomerization of beta-arrestins in living cells.
Department of Cell Biology, Institut Cochin, Paris, F-75014 France.
Arrestins are important proteins, which regulate the function of serpentine heptahelical receptors and contribute to multiple signaling pathways downstream of receptors. The ubiquitous beta-arrestins are believed to function exclusively as monomers, although self-association is assumed to control the activity of visual arrestin in the retina, where this isoform is particularly abundant. Here the oligomerization status of beta-arrestins was investigated using different approaches, including co-immunoprecipitation of epitope-tagged beta-arrestins and resonance energy transfer (BRET and FRET) in living cells. At steady state and at physiological concentrations, beta-arrestins constitutively form both homo- and hetero-oligomers. Co-expression of beta-arrestin2 and beta-arrestin1 prevented beta-arrestin1 accumulation into the nucleus, suggesting that hetero-oligomerization may have functional consequences. Our data clearly indicate that beta-arrestins can exist as homo- and hetero-oligomers in living cells and raise the hypothesis that the oligomeric state may regulate their subcellular distribution and functions.
J. Biol. Chem. 2005;280(48):40210-5.
Pubmed ID: 16199535