![]() A multipartite ligand-receptor complex, consisting of the extracellular ligands SAX-7, MNR-1, and LECT-2, along with the PVD guidance receptor DMA-1 and its partner HPO-30, directs the growth of PVD dendrites along the epidermis and body wall muscles. As a recently developed model system for studying dendritic morphogenesis, the PVD neuron elaborates complex dendritic arbors by extending a primary dendrite along the length of the worm, followed by orthogonal secondary, tertiary, and quaternary dendrites, which together create stereotyped “menorah”-like structures. elegans PVD neuron, the development of dendritic arbors requires two distinct, but cooperative, steps of actin assembly that involve the WRC, UNC-34 (Ena/VASP), and the actin-binding protein UNC-115 (abLIM). In this work, we provide evidence in support of this hypothesis showing that in the C. Therefore, it is likely neurons control morphological changes by dynamically orchestrating the formation of distinct types of actin networks in a coherent manner. Finally, branched actin networks generated via the Arp2/3 complex were found to provide sites for initiating new dendrite branches in Drosophila larval sensory da neurons. Furthermore, Abl tyrosine kinase has been shown to downregulate Ena activity while in parallel activating Rac/WAVE signaling, thus coordinating the balance of linear actin bundles and branched actin networks to regulate Drosophila axon patterning. For example, in dendritic spines of hippocampal pyramidal neurons, patches of loosely bundled linear actin filaments constitute the dendritic spine neck, whereas branched actin networks drive the expansion of spine heads. One hypothesis is that complex processes like neuronal morphogenesis integrate structurally distinct actin networks built by different actin regulators. It is, however, largely unknown how the activity of distinct actin regulators is coordinated in complex morphological processes. elegans embryogenesis, and collective axon extension in mice. For example, the direct interaction between the WRC and Ena/VASP was shown to play an important role in photoreceptor axon targeting, oogenesis, and macrophage migration in Drosophila, lamellipodia formation during ventral closure of C. Interestingly, these distinct actin regulators can act synergistically in several morphological processes. Ena/VASP can also be recruited by the Slit receptor, Robo, to mediate axon repulsion. In addition, a distinct actin elongation factor, Ena/VASP, can be recruited downstream of the Netrin receptor, DCC, to promote polarized filopodia formation during axon guidance. After being activated and recruited by diverse membrane receptors and the Rho family GTPase Rac1, the WRC can then stimulate the Arp2/3 complex to produce branched actin networks. One major signaling axis for neurite outgrowth is the activation and membrane recruitment of the actin nucleation promotion factor, the WAVE Regulatory Complex (WRC), a pentameric complex comprising Sra1/Cyfip1, Nap1/Hem-2, Abi, HSPC300, and WAVE/Scar. Similarly, activity-dependent dendritic arbor development also requires cytoskeletal signaling, including through Rho GTPase activity or microtubule stabilization. Dendrite morphogenesis is often guided by extracellular cues recognized through a number of cell surface receptors, such as Semaphorins, DSCAMs, and protocadherins, which in turn instruct activities of various intracellular molecules leading to cytoskeletal reorganization. In particular, the morphology of dendrites is key for neuronal signal transmission and integration. Neurite outgrowth and arborization are essential for the establishment and function of neural circuits. The Creative Commons Public Domain Dedication waiver ( ) applies to the data made available in this article, unless otherwise stated in a credit line to the data. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. Open AccessThis article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made.
0 Comments
Leave a Reply. |
Details
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |