Nagi Karim, Charfi Iness, Pineyro Graciela
Sainte-Justine Hospital Research Center, 3175 Cote Ste-Catherine, Montreal, QC, H3T 1C5, Canada.
Cell Mol Life Sci. 2015 Sep;72(18):3543-57. doi: 10.1007/s00018-015-1899-x. Epub 2015 Apr 22.
Kir3 channels control excitability in the nervous system and the heart. Their surface expression is strictly regulated, but mechanisms responsible for channel removal from the membrane remain incompletely understood. Using transfected cells, we show that Kir3.1/3.2 channels and delta opioid receptors (DORs) associate in a complex which persists during receptor activation, behaving as a scaffold that allows beta-arrestin (βarr) to interact with both signaling partners. This organization favored co-internalization of DORs and Kir3 channels in a βarr-dependent manner via a clathrin/dynamin-mediated endocytic path. Taken together, these findings identify a new way of modulating Kir3 channel availability at the membrane and assign a putatively novel role for βarrs in regulating canonical effectors for G protein-coupled receptors.
Kir3通道控制神经系统和心脏的兴奋性。它们的表面表达受到严格调控,但负责将通道从膜上移除的机制仍未完全了解。利用转染细胞,我们发现Kir3.1/3.2通道与δ阿片受体(DORs)形成复合物,该复合物在受体激活过程中持续存在,起到支架的作用,使β抑制蛋白(βarr)能够与两个信号转导伙伴相互作用。这种组织方式有利于DORs和Kir3通道通过网格蛋白/发动蛋白介导的内吞途径以βarr依赖的方式共同内化。综上所述,这些发现确定了一种调节膜上Kir3通道可用性的新方法,并赋予βarrs在调节G蛋白偶联受体的经典效应器方面一个可能的新作用。