Hayashi Kensuke
Faculty of Science and Technology, Sophia University, 7-1, Kioicho, Chiyoda-ku, Tokyo, 102-8554, Japan.
Adv Exp Med Biol. 2017;1006:83-101. doi: 10.1007/978-4-431-56550-5_6.
Drebrin is localized in actin-rich regions of neuronal and non-neuronal cells. In mature neurons, its localization is strictly restricted to the postsynaptic sites. In order to understand the function of drebrin in cells, many studies have been performed to examine the effect of overexpression or knocking down of drebrin in various cell types, including neurons, myoblasts, kidney cells, and intestinal epithelial cells. In most cases alteration of cell shape and impairment or facilitation of actin-based activities of these cells were observed. Interestingly, overexpression of drebrin in matured neurons results in the alteration in dendritic spine morphology. Further studies have shown alteration in the localization of postsynaptic receptors and even changes in synaptic transmission caused by drebrin overexpression or depletion in neurons. These drebrin's effects are thought to come from drebrin's actin-cross-linking activity or competitive binding to actin against tropomyosin, fascin, and α-actinin. Furthermore, drebrin binds to various molecules, such as homer, EB3, and cell-cell junctional proteins, indicating that drebrin is a multifunctional cytoskeletal regulator.
双调蛋白定位于神经元和非神经元细胞中富含肌动蛋白的区域。在成熟神经元中，其定位严格局限于突触后位点。为了了解双调蛋白在细胞中的功能，人们进行了许多研究，以检测双调蛋白在包括神经元、成肌细胞、肾细胞和肠上皮细胞在内的各种细胞类型中过表达或敲低的效果。在大多数情况下，观察到这些细胞的形态改变以及基于肌动蛋白的活性受损或增强。有趣的是，在成熟神经元中双调蛋白的过表达会导致树突棘形态的改变。进一步的研究表明，神经元中双调蛋白的过表达或缺失会导致突触后受体定位的改变，甚至突触传递的变化。双调蛋白的这些作用被认为源于双调蛋白的肌动蛋白交联活性或与肌动蛋白竞争结合原肌球蛋白、细丝蛋白和α-辅肌动蛋白。此外，双调蛋白与多种分子结合，如亲 Homer 蛋白（homer）、EB3 和细胞间连接蛋白，这表明双调蛋白是一种多功能细胞骨架调节剂。
