Vessey John P, Karra Daniela
Department of Neural Cell Biology, Center for Brain Research, Medical University of Vienna, Vienna, Austria.
J Neurochem. 2007 Jul;102(2):324-32. doi: 10.1111/j.1471-4159.2007.04662.x.
The dendritic arbor is responsible for receiving and consolidating neuronal input. Outgrowth and morphogenesis of the arbor are complex stages of development that are poorly understood. However, recent findings have identified synaptic scaffolding proteins as novel regulators of these important events. Scaffolding proteins are enriched in the post-synaptic density where they bind and bring into close proximity neurotransmitter receptors, signaling molecules, and regulators of the actin cytoskeleton. This property is important for dendritic spine morphogenesis and maintenance in the mature neuron. Scaffolding proteins are now being described as key regulators of neurite outgrowth, dendritic development, and pattern formation in immature neurons. These proteins, which include post-synaptic-95, Shank and Densin-180, as well as many of their interacting partners, appear to regulate both the microtubule and actin cytoskeleton to influence dendrite morphology. Through a large array of protein-protein interaction domains, scaffolding proteins are able to form large macromolecular complexes that include cytoskeletal motor proteins as well as microtubule and actin regulatory molecules. Together, the new findings form a persuasive argument that scaffolding proteins deliver critical regulatory elements to sites of dendritic outgrowth and branching to modulate the formation and maintenance of the dendritic arbor.
树突分支负责接收和整合神经元输入。树突分支的生长和形态发生是发育过程中复杂的阶段，目前人们对此了解甚少。然而，最近的研究发现，突触支架蛋白是这些重要事件的新型调节因子。支架蛋白在突触后致密区富集，在那里它们结合神经递质受体、信号分子和肌动蛋白细胞骨架调节因子，并使它们紧密靠近。这一特性对于成熟神经元中树突棘的形态发生和维持很重要。目前，支架蛋白被认为是未成熟神经元中神经突生长、树突发育和模式形成的关键调节因子。这些蛋白质包括突触后致密蛋白95、Shank和Densin-180，以及它们的许多相互作用伙伴，似乎通过调节微管和肌动蛋白细胞骨架来影响树突形态。通过大量的蛋白质-蛋白质相互作用结构域，支架蛋白能够形成大型大分子复合物，其中包括细胞骨架运动蛋白以及微管和肌动蛋白调节分子。这些新发现共同构成了一个有说服力的观点，即支架蛋白将关键调节元件传递到树突生长和分支部位，以调节树突分支的形成和维持。
