Effect of homodimerization of G-protein coupled receptors on the cell signaling and the affinity to ligands

功能性g蛋白偶联受体被认为在二聚化时具有功能。然而，在受体二聚体中，每个亚基（一个受体分子）分别与一个激动剂结合。当与与α - 1a受体相互作用的Snapin共表达时，Sanpin也会二聚，并且每个Snapin都可以与受体结合。因此α - 1a受体也可以形成调光体。有趣的是，与Snapin共存的受体二聚体只能与一种激动剂结合，这表明当与Snapin共存时，功能二聚体可能与不含Snapin的二聚体形成不同的结构。

Functional G-protein coupled receptors are believed to be functional when dimerized. Still, in the receptor dimer, each subunit(one receptor molecule) binds to one agonist, respectively. When coexpressed with Snapin, which intereacts with alpha-1A receptors, Sanpin also dimerizes, and each Snapin can bind to the receptor. Thus, alpha-1A receptor can also form dimmer. Interestingly, the receptor dimer with Snapin can bin only to one agonist, suggesting that the functional dimmer when coexisted with Snapin may form a different structure from the dimmer without Snapin.