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Molecular basis of CLICK-III/CaMKIγ-mediated dendritogenesis in developing cortical neurons
| Content Provider | Semantic Scholar |
|---|---|
| Author | Suzuki, Kanzo Takemoto-Kimura, Sayaka Kamijo, Satoshi Inoue, Masatoshi Bito, Haruhiko |
| Copyright Year | 2011 |
| Abstract | s / Neuroscience Research 71S (2011) e46–e107 e67 myenteric plexus formation, but also for development of the submucosal plexus. Research fund: KAKENHI22122005 (H.E.). doi:10.1016/j.neures.2011.07.283 O3-C-3-3 Draxin has a unique role for the guidance of thalamocortical projections Yohei Shinmyo 1 , MD Riyadh 1,2, Mahmud Hossain 1,2, Giasuddin Ahmed 1, Iftekhar Bin Naser 1, Xiaohong Song 1,2, Hirohide Takebayashi 3, Kunimasa Ohta 1, Hideaki Tanaka 1,2 1 Dept. of Dev. Neurobiol., Kumamoto Univ., Kumamoto, Japan 2 GCOE Kumamoto Univ., Kumamoto, Japan 3 Dept. of Morphol. Neural Sci., Kumamoto Univ., Kumamoto, Japan The mammalian neocortex is a complex six-layered structure that contains distinct populations of projection neurons in different layers. We previously showed that a chemorepulsive protein, draxin, is required for the midline crossing of corpus callosum axons in the neocortex. Here, we report that draxin has a critical role for the projections of corticothalamic and thalamocortical axons. draxin is strongly expressed in early-born cortical neurons, including subplate and Cajal-Retzius cells, and weakly expressed in the ventral telencephalon and dorsal thalamus. draxin deficient mice showed severe defects in the guidance of these axons: thalamocortical and corticothalamic axons followed an ectopic route through the external capsule instead of projecting to the cortex and thalamus, respectively. We found that thalamic axons showed a pathfinding error in the internal capsule region at embryonic day 14.5, when cortical axon pathfinding still appeared normal. This suggests that primary defects in the thalamocortical axon pathfinding cause misprojection of cortical axons. In addition, we showed that draxin binds to thalamocortical axons and has inhibitory effects for neurite outgrowth from thalamic explants. The thalamocortical phenotype in draxin mutants seems to be rescued by the transgenic expression of draxin in the neocortex. Thus, we propose that draxin repulsion from the neocortex may be essential for proper guidance of thalamocortical axons. Research fund: KAKENHI217003822. doi:10.1016/j.neures.2011.07.284 O3-C-3-4 Molecular basis of CLICK-III/CaMKI -mediated dendritogenesis in developing cortical neurons Kanzo Suzuki 1 , Sayaka Takemoto-Kimura 1,2, Satoshi Kamijo 1, Masatoshi Inoue 1, Hajime Fujii 1, Natsumi Ageta-Ishihara 1,3, Hiroyuki Okuno 1, Haruhiko Bito 1,4 1 Dept. of Neurochem., Grad. Sch. of Med., University of Tokyo, Bunkyoku, Japan 2 PRESTO-JST 3 Div. of Biol. Sci., Grad. Sch. Sci., Nagoya University 4 CREST-JST Ca2+ signaling plays an important role in axon and dendritic growth. Ca2+/calmodulin-dependent protein kinases (CaMKs) represent major enzymatic targets for an activated Ca2+/calmodulin (CaM) complex that is generated by intracellular calcium rise. Recently, we reported distinct roles for CaMKI and isoforms in coordinating axonal and dendritic morphogenesis, respectively, in cultured cortical neurons (Ageta-Ishihara et al., J. Neurosci., 2009; Takemoto-Kimura et al., Neuron, 2007). However, the molecular determinants involved in axonogenetic and dendritogenetic selectivity of CaMKI and CaMKI have remained unsolved. We here examined the enzymological mechanisms that mediated BDNF-dependent dendritogenesis stimulated by a lipid-raft-anchored CLICK-III/CaMKI . We found that CLICKIII/CaMKI -knockout neurons showed shorter dendrites and lacked responses to BDNF in vitro culture. In this condition, the effect of BDNF on the kinase activity was characterized in cortical neurons. To investigate the molecular basis of this specificity, we measured the Ca2+/CaM-dependence of either purified CaMKI or CaMKI activities in vitro. Intriguingly, purified preparations of either CaMKI or CaMKI that were preactivated by a CaMKK activity revealed distinguishable bell-shaped calcium response curves, which were modulated in the presence of various concentrations of CaM. Finally, we examined the substrate specificities for CaMKI and CaMKI using biochemical analysis in vitro. Existence of specific substrates for CaMKI was suggested in the mouse brain lysates. Furthermore, distinctive substrate signatures were identified for CaMKI and CaMKI based on peptide library profiling analysis. Taken together, these findings elucidate key features of biochemical mechanisms underlying BDNF-mediated dendritic growth in developing cortical neurons. doi:10.1016/j.neures.2011.07.285 O3-C-4-1 Draxin inhibits axonal outgrowth through the netrin receptor DCC Giasuddin Ahmed 1 , Yohei Shinmyo 1, Kunimasa Ohta 1, Shahidul M Islam 2, Mahmud Hossain 1, Iftekhar Bin Naser 1, Asrafuzzaman Riyadh 1, Yuhong Su 3, Sanbing Zhang 4, Marc Tessier-Lavigne 5, Hideaki Tanaka 1 1 Div. of Dev. Neurobiol., Grad. Sch. of Med., Kumamoto Univ., Kumamoto, Japan 2 Yale University, USA 3 Hebei University, China 4 Third Hospital, Shijiazhuang, Hebei, China 5 Rockefeller University, USA We recently reported the discovery of novel axon guidance protein, draxin. Draxin is essential for the formation of forebrain commissures and can mediate repulsion of netrin-stimulated spinal commissural axons. Here, we report the identification of draxin receptors. We found that draxin binding is restricted to multiple netrin receptors: DCC, Neogenin, and UNC5s (H1, H2, H3). Among the netrin receptors, only DCC knockout mice phenotype in forebrain commissures is similar with draxin knockouts. Hence, we show here the functional importance of draxin/DCC interaction. Draxin binds with subnanomolar affinity to the netrin receptor DCC, in a region of DCC distinct from its netrin-binding domain. In vitro, neurite outgrowth from cortical explants of DCC knockout mice is significantly less inhibited by draxin, when compared with neurites from explants of wild type mice. Furthermore, in comparison with wild type, the growth cone collapse in response to draxin is largely abolished in DCC deficient cortical neurons. In vivo, double heteros of draxin/DCC mice show markedly higher frequency of complete agenesis of corpus callosum than either of the single hetero. These results identify DCC as a convergent receptor for netrin and for draxin in axon growth and guidance. Research fund: Grants-in-aid from the Ministry of Education, Science, Sports, and Culture of Japan (MEXT), by the 21st Century COE Program and by the Global COE Program (Cell Fate Regulation Research and Education Unit), MEXT, Japan, and by Takeda Science Foundation. doi:10.1016/j.neures.2011.07.286 O3-C-4-2 Evolution of developmental plan for peripheral nervous system in amniote trunk region Masahumi Kawaguchi 1 , Aki Watanabe 2, Hiromi Makiya 2, Hiroshi Nagashima 3, Takahiko Kawasaki 4, Tatsumi Hirata 4, Tomoyuki Masuda 5, Shigeru Kuratani 3, Yasunori Murakami 2 1 Centre for Marine Environmental Studies, Ehime University, Matsuyama, Japan 2 Graduate School of Science and Engineering, Ehime University, Matsuyama, Japan 3 Laboratory for Evolutionary Morphology, RIKEN CDB, Kobe, Japan 4 Division of Brain Function, National Institute of Genetics, Mishima, Japan 5 Department of Anatomy, Fukushima Medical University, Fukushima, Japan It has been known that the morphology of peripheral nerves in the trunk region has been highly conserved through vetebrate species. Motoneurons localize at the ventral side of spinal cord and exit ventrally, while sensory neurons locate in the dorsal root ganglion (DRG) and enter into spinal cord from the dorsal side. However, there are some exceptions. For instance, in adult turtle, motoneurons are absent in thoracic spinal cord due to the lack of trunk musculature. To explore the fundamental and modified plans of axonal scaffolding in the vertebrate trunk region, we studied the developmental process of turtle peripheral nerve and compared it to the other amniotes such as mouse, chicken and lizard. Through this analysis, we found the two types of developmental plan; in the mouse and chicken embryos, the dorsal ramus of both motor and sensory neurons initially exited from spinal cord or DRG, and then turned dorsally beneath the ventral side of DRG. On the other hand, in the turtle and lizard embryos, the dorsal ramus of the spinal nerve elongated toward the dorsolateral side across DRG, without descending ventrally. In addition, only a small number of dorsal motor branches were observed in turtles. To clarify the mechanism that constructs differential peripheral nervous system, we compared the expression pattern of axon guidance molecules among mouse, chicken and turtle. In the turtle embryos, the expression levels of Sema3A, a repulsive factor for the neurons of DRG, and Fgf8, a chemoattractant for the dorsal motor nerve, were decreased in the dermatome and dermomyotome, respectively. Furthermore, implantation of FGF8 soaked bead induced the abnormal plexus orienting to the implanted bead. These data suggest that the developmental plan of turtle nervous system has been changed based on the modification of axonal guidance environment. Research fund: KAKENHI (21770238). doi:10.1016/j.neures.2011.07.287 |
| File Format | PDF HTM / HTML |
| DOI | 10.1016/j.neures.2011.07.285 |
| Volume Number | 71 |
| Alternate Webpage(s) | https://api.elsevier.com/content/article/pii/S0168010211004688 |
| Alternate Webpage(s) | https://www.sciencedirect.com/science/article/pii/S0168010211004688?dgcid=api_sd_search-api-endpoint |
| Journal | Neuroscience Research |
| Language | English |
| Access Restriction | Open |
| Content Type | Text |
| Resource Type | Article |
