The Abrogation of Phosphorylation Plays a Relevant Role in the CCR5 Signalosome Formation with Natural Antibodies to CCR5.

The exposure to CCR5 (CC chemokine receptor 5) specific natural antibodies in vitro produces a Class B β-arrestin2-dependent CCR5 retention with the aid of ERK1, due to the formation of a CCR5 signalosome, which remains stable for at least 48 h. Considering that β-arrestins and MAPKs are receptive to environmental signals, their signal complexes could be one of the key junction for GPCRs internalization related signal transduction. Here, we demonstrate that, in T cells, the phosphorylation status of either CCR5 receptor or ERK1 protein is necessary to drive the internalized receptor into the early endosomes, forming the CCR5 signalosome. In particular, our data show that β-arrestin2/ERK1 complex is a relevant transducer in the CCR5 signaling pathway. Understanding the mechanism of CCR5 regulation is essential for many inflammatory disorders, tumorigenesis and viral infection such as HIV.