Allosteric interactions between the oxytocin receptor and the beta(2)-adrenergic receptor in the modulation of ERK1/2 activation are mediated by heterodimerization

作者：Wrzal Paulina K; Devost Dominic; Petrin Darlaine; Goupil Eugenie; Iorio Morin Christian; Laporte Stephane A; Zingg Hans H^*; Hebert Terence E

来源：Cellular Signalling, 2012, 24(1): 342-350.

DOI：10.1016/j.cellsig.2011.09.020

• Oxytocin receptor
• beta(2)-adrenergic receptor
• ERK1/2
• Allosteric modulation
• Signalling
• Dimerization

The oxytocin receptor (OTR) and the beta(2)-adrenergic receptor (beta(2)AR) are key regulators of uterine contraction. These two receptors are targets of tocolytic agents used to inhibit pre-term labor. Our recent study on the nature of OTR- and beta(2)AR-mediated ERK1/2 activation in human hTERT-C3 myometrial cells suggested the presence of an OTR/beta(2)AR hetero-oligomeric complex (see companion article). The goal of this study was to investigate potential allosteric interactions between OTR and beta(2)AR and establish the nature of the interactions between these receptors in myometrial cells. We found that OTR-mediated ERK1/2 activation was attenuated significantly when cells were pretreated with the beta(2)AR agonist isoproterenol or two antagonists, propranolol or timolol. In contrast, pretreatment of cells with a third beta(2)AR antagonist, atenolol resulted in an increase in OTR-mediated ERK1/2 activation. Similarly, beta(2)AR-mediated ERK1/2 activation was strongly attenuated by pretreatment with the OTR antagonists, atosiban and OTA. Physical interactions between OTR and beta(2)AR were demonstrated using co-immunoprecipitation, bioluminescence resonance energy transfer (BRET) and protein-fragment complementation (PCA) assays in HEK 293 cells, the latter experiments indicating the interactions between the two receptors were direct. Our analyses suggest physical interactions between OTR and beta(2)AR in the context of a new heterodimer pair lie at the heart of the allosteric effects.

• 出版日期2012-1