TY - JOUR AB - The plant-signaling molecule auxin triggers fast and slow cellular responses across land plants and algae. The nuclear auxin pathway mediates gene expression and controls growth and development in land plants, but this pathway is absent from algal sister groups. Several components of rapid responses have been identified in Arabidopsis, but it is unknown if these are part of a conserved mechanism. We recently identified a fast, proteome-wide phosphorylation response to auxin. Here, we show that this response occurs across 5 land plant and algal species and converges on a core group of shared targets. We found conserved rapid physiological responses to auxin in the same species and identified rapidly accelerated fibrosarcoma (RAF)-like protein kinases as central mediators of auxin-triggered phosphorylation across species. Genetic analysis connects this kinase to both auxin-triggered protein phosphorylation and rapid cellular response, thus identifying an ancient mechanism for fast auxin responses in the green lineage. AU - Kuhn, Andre AU - Roosjen, Mark AU - Mutte, Sumanth AU - Dubey, Shiv Mani AU - Carrillo Carrasco, Vanessa Polet AU - Boeren, Sjef AU - Monzer, Aline AU - Koehorst, Jasper AU - Kohchi, Takayuki AU - Nishihama, Ryuichi AU - Fendrych, Matyas AU - Sprakel, Joris AU - Friml, Jiří AU - Weijers, Dolf ID - 14826 IS - 1 JF - Cell KW - General Biochemistry KW - Genetics and Molecular Biology SN - 0092-8674 TI - RAF-like protein kinases mediate a deeply conserved, rapid auxin response VL - 187 ER - TY - JOUR AB - Little is known about the critical metabolic changes that neural cells have to undergo during development and how temporary shifts in this program can influence brain circuitries and behavior. Inspired by the discovery that mutations in SLC7A5, a transporter of metabolically essential large neutral amino acids (LNAAs), lead to autism, we employed metabolomic profiling to study the metabolic states of the cerebral cortex across different developmental stages. We found that the forebrain undergoes significant metabolic remodeling throughout development, with certain groups of metabolites showing stage-specific changes, but what are the consequences of perturbing this metabolic program? By manipulating Slc7a5 expression in neural cells, we found that the metabolism of LNAAs and lipids are interconnected in the cortex. Deletion of Slc7a5 in neurons affects the postnatal metabolic state, leading to a shift in lipid metabolism. Additionally, it causes stage- and cell-type-specific alterations in neuronal activity patterns, resulting in a long-term circuit dysfunction. AU - Knaus, Lisa AU - Basilico, Bernadette AU - Malzl, Daniel AU - Gerykova Bujalkova, Maria AU - Smogavec, Mateja AU - Schwarz, Lena A. AU - Gorkiewicz, Sarah AU - Amberg, Nicole AU - Pauler, Florian AU - Knittl-Frank, Christian AU - Tassinari, Marianna AU - Maulide, Nuno AU - Rülicke, Thomas AU - Menche, Jörg AU - Hippenmeyer, Simon AU - Novarino, Gaia ID - 12802 IS - 9 JF - Cell KW - General Biochemistry KW - Genetics and Molecular Biology SN - 0092-8674 TI - Large neutral amino acid levels tune perinatal neuronal excitability and survival VL - 186 ER - TY - JOUR AB - How tissues acquire complex shapes is a fundamental question in biology and regenerative medicine. Zebrafish semicircular canals form from invaginations in the otic epithelium (buds) that extend and fuse to form the hubs of each canal. We find that conventional actomyosin-driven behaviors are not required. Instead, local secretion of hyaluronan, made by the enzymes uridine 5′-diphosphate dehydrogenase (ugdh) and hyaluronan synthase 3 (has3), drives canal morphogenesis. Charged hyaluronate polymers osmotically swell with water and generate isotropic extracellular pressure to deform the overlying epithelium into buds. The mechanical anisotropy needed to shape buds into tubes is conferred by a polarized distribution of actomyosin and E-cadherin-rich membrane tethers, which we term cytocinches. Most work on tissue morphogenesis ascribes actomyosin contractility as the driving force, while the extracellular matrix shapes tissues through differential stiffness. Our work inverts this expectation. Hyaluronate pressure shaped by anisotropic tissue stiffness may be a widespread mechanism for powering morphological change in organogenesis and tissue engineering. AU - Munjal, Akankshi AU - Hannezo, Edouard B AU - Tsai, Tony Y.C. AU - Mitchison, Timothy J. AU - Megason, Sean G. ID - 10573 IS - 26 JF - Cell SN - 0092-8674 TI - Extracellular hyaluronate pressure shaped by cellular tethers drives tissue morphogenesis VL - 184 ER - TY - JOUR AB - Eukaryotic DNA-binding proteins operate in the context of chromatin, where nucleosomes are the elementary building blocks. Nucleosomal DNA is wrapped around a histone core, thereby rendering a large fraction of the DNA surface inaccessible to DNA-binding proteins. Nevertheless, first responders in DNA repair and sequence-specific transcription factors bind DNA target sites obstructed by chromatin. While early studies examined protein binding to histone-free DNA, it is only now beginning to emerge how DNA sequences are interrogated on nucleosomes. These readout strategies range from the release of nucleosomal DNA from histones, to rotational/translation register shifts of the DNA motif, and nucleosome-specific DNA binding modes that differ from those observed on naked DNA. Since DNA motif engagement on nucleosomes strongly depends on position and orientation, we argue that motif location and nucleosome positioning co-determine protein access to DNA in transcription and DNA repair. AU - Michael, Alicia AU - Thomä, Nicolas H. ID - 15151 IS - 14 JF - Cell KW - General Biochemistry KW - Genetics and Molecular Biology SN - 0092-8674 TI - Reading the chromatinized genome VL - 184 ER - TY - JOUR AB - The endosomal sorting complex required for transport-III (ESCRT-III) catalyzes membrane fission from within membrane necks, a process that is essential for many cellular functions, from cell division to lysosome degradation and autophagy. How it breaks membranes, though, remains unknown. Here, we characterize a sequential polymerization of ESCRT-III subunits that, driven by a recruitment cascade and by continuous subunit-turnover powered by the ATPase Vps4, induces membrane deformation and fission. During this process, the exchange of Vps24 for Did2 induces a tilt in the polymer-membrane interface, which triggers transition from flat spiral polymers to helical filament to drive the formation of membrane protrusions, and ends with the formation of a highly constricted Did2-Ist1 co-polymer that we show is competent to promote fission when bound on the inside of membrane necks. Overall, our results suggest a mechanism of stepwise changes in ESCRT-III filament structure and mechanical properties via exchange of the filament subunits to catalyze ESCRT-III activity. AU - Pfitzner, Anna-Katharina AU - Mercier, Vincent AU - Jiang, Xiuyun AU - Moser von Filseck, Joachim AU - Baum, Buzz AU - Šarić, Anđela AU - Roux, Aurélien ID - 10348 IS - 5 JF - Cell KW - general biochemistry KW - genetics and molecular biology SN - 0092-8674 TI - An ESCRT-III polymerization sequence drives membrane deformation and fission VL - 182 ER - TY - JOUR AU - Schwayer, Cornelia AU - Shamipour, Shayan AU - Pranjic-Ferscha, Kornelija AU - Schauer, Alexandra AU - Balda, M AU - Tada, M AU - Matter, K AU - Heisenberg, Carl-Philipp J ID - 7001 IS - 4 JF - Cell SN - 0092-8674 TI - Mechanosensation of tight junctions depends on ZO-1 phase separation and flow VL - 179 ER - TY - JOUR AU - Kopf, Aglaja AU - Sixt, Michael K ID - 6877 IS - 1 JF - Cell SN - 0092-8674 TI - The neural crest pitches in to remove apoptotic debris VL - 179 ER - TY - JOUR AB - The exchange of metabolites between the mitochondrial matrix and the cytosol depends on β-barrel channels in the outer membrane and α-helical carrier proteins in the inner membrane. The essential translocase of the inner membrane (TIM) chaperones escort these proteins through the intermembrane space, but the structural and mechanistic details remain elusive. We have used an integrated structural biology approach to reveal the functional principle of TIM chaperones. Multiple clamp-like binding sites hold the mitochondrial membrane proteins in a translocation-competent elongated form, thus mimicking characteristics of co-translational membrane insertion. The bound preprotein undergoes conformational dynamics within the chaperone binding clefts, pointing to a multitude of dynamic local binding events. Mutations in these binding sites cause cell death or growth defects associated with impairment of carrier and β-barrel protein biogenesis. Our work reveals how a single mitochondrial “transfer-chaperone” system is able to guide α-helical and β-barrel membrane proteins in a “nascent chain-like” conformation through a ribosome-free compartment. AU - Weinhäupl, Katharina AU - Lindau, Caroline AU - Hessel, Audrey AU - Wang, Yong AU - Schütze, Conny AU - Jores, Tobias AU - Melchionda, Laura AU - Schönfisch, Birgit AU - Kalbacher, Hubert AU - Bersch, Beate AU - Rapaport, Doron AU - Brennich, Martha AU - Lindorff-Larsen, Kresten AU - Wiedemann, Nils AU - Schanda, Paul ID - 8436 IS - 5 JF - Cell KW - General Biochemistry KW - Genetics and Molecular Biology SN - 0092-8674 TI - Structural basis of membrane protein chaperoning through the mitochondrial intermembrane space VL - 175 ER - TY - JOUR AB - Human cancer cells bear complex chromosome rearrangements that can be potential drivers of cancer development. However, the molecular mechanisms underlying these rearrangements have been unclear. Zhang et al. use a new technique combining live-cell imaging and single-cell sequencing to demonstrate that chromosomes mis-segregated to micronuclei frequently undergo chromothripsis-like rearrangements in the subsequent cell cycle. AU - Hatch, Emily M. AU - HETZER, Martin W ID - 11073 IS - 7 JF - Cell KW - General Biochemistry KW - Genetics and Molecular Biology SN - 0092-8674 TI - Linking micronuclei to chromosome fragmentation VL - 161 ER - TY - JOUR AB - The spindle assembly checkpoint prevents separation of sister chromatids until each kinetochore is attached to the mitotic spindle. Rodriguez-Bravo et al. report that the nuclear pore complex scaffolds spindle assembly checkpoint signaling in interphase, providing a store of inhibitory signals that limits the speed of the subsequent mitosis. AU - Buchwalter, Abigail AU - HETZER, Martin W ID - 11080 IS - 5 JF - Cell KW - General Biochemistry KW - Genetics and Molecular Biology SN - 0092-8674 TI - Nuclear pores set the speed limit for mitosis VL - 156 ER - TY - JOUR AU - Linneweber, Gerit A. AU - Jacobson, Jake AU - Busch, Karl Emanuel AU - Hudry, Bruno AU - Christov, Christo P. AU - Dormann, Dirk AU - Yuan, Michaela AU - Otani, Tomoki AU - Knust, Elisabeth AU - de Bono, Mario AU - Miguel-Aliaga, Irene ID - 6122 IS - 1-2 JF - Cell SN - 0092-8674 TI - Neuronal control of metabolism through nutrient-dependent modulation of tracheal branching VL - 156 ER - TY - JOUR AB - Dnmt1 epigenetically propagates symmetrical CG methylation in many eukaryotes. Their genomes are typically depleted of CG dinucleotides because of imperfect repair of deaminated methylcytosines. Here, we extensively survey diverse species lacking Dnmt1 and show that, surprisingly, symmetrical CG methylation is nonetheless frequently present and catalyzed by a different DNA methyltransferase family, Dnmt5. Numerous Dnmt5-containing organisms that diverged more than a billion years ago exhibit clustered methylation, specifically in nucleosome linkers. Clustered methylation occurs at unprecedented densities and directly disfavors nucleosomes, contributing to nucleosome positioning between clusters. Dense methylation is enabled by a regime of genomic sequence evolution that enriches CG dinucleotides and drives the highest CG frequencies known. Species with linker methylation have small, transcriptionally active nuclei that approach the physical limits of chromatin compaction. These features constitute a previously unappreciated genome architecture, in which dense methylation influences nucleosome positions, likely facilitating nuclear processes under extreme spatial constraints. AU - Huff, Jason T. AU - Zilberman, Daniel ID - 9458 IS - 6 JF - Cell SN - 0092-8674 TI - Dnmt1-independent CG methylation contributes to nucleosome positioning in diverse eukaryotes VL - 156 ER - TY - JOUR AB - Intracellular proteins with long lifespans have recently been linked to age-dependent defects, ranging from decreased fertility to the functional decline of neurons. Why long-lived proteins exist in metabolically active cellular environments and how they are maintained over time remains poorly understood. Here, we provide a system-wide identification of proteins with exceptional lifespans in the rat brain. These proteins are inefficiently replenished despite being translated robustly throughout adulthood. Using nucleoporins as a paradigm for long-term protein persistence, we found that nuclear pore complexes (NPCs) are maintained over a cell’s life through slow but finite exchange of even its most stable subcomplexes. This maintenance is limited, however, as some nucleoporin levels decrease during aging, providing a rationale for the previously observed age-dependent deterioration of NPC function. Our identification of a long-lived proteome reveals cellular components that are at increased risk for damage accumulation, linking long-term protein persistence to the cellular aging process. AU - Toyama, Brandon H. AU - Savas, Jeffrey N. AU - Park, Sung Kyu AU - Harris, Michael S. AU - Ingolia, Nicholas T. AU - Yates, John R. AU - HETZER, Martin W ID - 11087 IS - 5 JF - Cell KW - General Biochemistry KW - Genetics and Molecular Biology SN - 0092-8674 TI - Identification of long-lived proteins reveals exceptional stability of essential cellular structures VL - 154 ER - TY - JOUR AB - During mitotic exit, missegregated chromosomes can recruit their own nuclear envelope (NE) to form micronuclei (MN). MN have reduced functioning compared to primary nuclei in the same cell, although the two compartments appear to be structurally comparable. Here we show that over 60% of MN undergo an irreversible loss of compartmentalization during interphase due to NE collapse. This disruption of the MN, which is induced by defects in nuclear lamina assembly, drastically reduces nuclear functions and can trigger massive DNA damage. MN disruption is associated with chromatin compaction and invasion of endoplasmic reticulum (ER) tubules into the chromatin. We identified disrupted MN in both major subtypes of human non-small-cell lung cancer, suggesting that disrupted MN could be a useful objective biomarker for genomic instability in solid tumors. Our study shows that NE collapse is a key event underlying MN dysfunction and establishes a link between aberrant NE organization and aneuploidy. AU - Hatch, Emily M. AU - Fischer, Andrew H. AU - Deerinck, Thomas J. AU - HETZER, Martin W ID - 11085 IS - 1 JF - Cell KW - General Biochemistry KW - Genetics and Molecular Biology SN - 0092-8674 TI - Catastrophic nuclear envelope collapse in cancer cell micronuclei VL - 154 ER - TY - JOUR AB - Nucleosome remodelers of the DDM1/Lsh family are required for DNA methylation of transposable elements, but the reason for this is unknown. How DDM1 interacts with other methylation pathways, such as small-RNA-directed DNA methylation (RdDM), which is thought to mediate plant asymmetric methylation through DRM enzymes, is also unclear. Here, we show that most asymmetric methylation is facilitated by DDM1 and mediated by the methyltransferase CMT2 separately from RdDM. We find that heterochromatic sequences preferentially require DDM1 for DNA methylation and that this preference depends on linker histone H1. RdDM is instead inhibited by heterochromatin and absolutely requires the nucleosome remodeler DRD1. Together, DDM1 and RdDM mediate nearly all transposon methylation and collaborate to repress transposition and regulate the methylation and expression of genes. Our results indicate that DDM1 provides DNA methyltransferases access to H1-containing heterochromatin to allow stable silencing of transposable elements in cooperation with the RdDM pathway. AU - Zemach, Assaf AU - Kim, M. Yvonne AU - Hsieh, Ping-Hung AU - Coleman-Derr, Devin AU - Eshed-Williams, Leor AU - Thao, Ka AU - Harmer, Stacey L. AU - Zilberman, Daniel ID - 9459 IS - 1 JF - Cell SN - 0092-8674 TI - The Arabidopsis nucleosome remodeler DDM1 allows DNA methyltransferases to access H1-containing heterochromatin VL - 153 ER - TY - JOUR AB - Nuclear export of mRNAs is thought to occur exclusively through nuclear pore complexes. In this issue of Cell, Speese et al. identify an alternate pathway for mRNA export in muscle cells where ribonucleoprotein complexes involved in forming neuromuscular junctions transit the nuclear envelope by fusing with and budding through the nuclear membrane. AU - Hatch, Emily M. AU - HETZER, Martin W ID - 11090 IS - 4 JF - Cell KW - General Biochemistry KW - Genetics and Molecular Biology SN - 0092-8674 TI - RNP export by nuclear envelope budding VL - 149 ER - TY - JOUR AB - Nuclear pore complexes have recently been shown to play roles in gene activation; however their potential involvement in metazoan transcription remains unclear. Here we show that the nucleoporins Sec13, Nup98, and Nup88, as well as a group of FG-repeat nucleoporins, bind to the Drosophila genome at functionally distinct loci that often do not represent nuclear envelope contact sites. Whereas Nup88 localizes to silent loci, Sec13, Nup98, and a subset of FG-repeat nucleoporins bind to developmentally regulated genes undergoing transcription induction. Strikingly, RNAi-mediated knockdown of intranuclear Sec13 and Nup98 specifically inhibits transcription of their target genes and prevents efficient reactivation of transcription after heat shock, suggesting an essential role of NPC components in regulating complex gene expression programs of multicellular organisms. AU - Capelson, Maya AU - Liang, Yun AU - Schulte, Roberta AU - Mair, William AU - Wagner, Ulrich AU - HETZER, Martin W ID - 11102 IS - 3 JF - Cell KW - General Biochemistry KW - Genetics and Molecular Biology SN - 0092-8674 TI - Chromatin-bound nuclear pore components regulate gene expression in higher eukaryotes VL - 140 ER - TY - JOUR AB - In metazoa, nuclear pore complexes (NPCs) assemble from disassembled precursors into a reforming nuclear envelope (NE) at the end of mitosis and into growing intact NEs during interphase. Here, we show via RNAi-mediated knockdown that ELYS, a nucleoporin critical for the recruitment of the essential Nup107/160 complex to chromatin, is required for NPC assembly at the end of mitosis but not during interphase. Conversely, the transmembrane nucleoporin POM121 is critical for the incorporation of the Nup107/160 complex into new assembly sites specifically during interphase. Strikingly, recruitment of the Nup107/160 complex to an intact NE involves a membrane curvature-sensing domain of its constituent Nup133, which is not required for postmitotic NPC formation. Our results suggest that in organisms with open mitosis, NPCs assemble via two distinct mechanisms to accommodate cell cycle-dependent differences in NE topology. AU - Doucet, Christine M. AU - Talamas, Jessica A. AU - HETZER, Martin W ID - 11101 IS - 6 JF - Cell KW - General Biochemistry KW - Genetics and Molecular Biology SN - 0092-8674 TI - Cell cycle-dependent differences in nuclear pore complex assembly in metazoa VL - 141 ER - TY - JOUR AB - By combining gene expression profiling with image registration, Tomer et al. (2010) find that the mushroom body of the segmented worm Platynereis dumerilii shares many features with the mammalian cerebral cortex. The authors propose that the mushroom body and cortex evolved from the same structure in the common ancestor of vertebrates and invertebrates. AU - Sweeney, Lora Beatrice Jaeger AU - Luo, Liqun ID - 7703 IS - 5 JF - Cell SN - 0092-8674 TI - ‘Fore brain: A hint of the ancestral cortex VL - 142 ER - TY - JOUR AB - In dividing cells, nuclear pore complexes (NPCs) disassemble during mitosis and reassemble into the newly forming nuclei. However, the fate of nuclear pores in postmitotic cells is unknown. Here, we show that NPCs, unlike other nuclear structures, do not turn over in differentiated cells. While a subset of NPC components, like Nup153 and Nup50, are continuously exchanged, scaffold nucleoporins, like the Nup107/160 complex, are extremely long-lived and remain incorporated in the nuclear membrane during the entire cellular life span. Besides the lack of nucleoporin expression and NPC turnover, we discovered an age-related deterioration of NPCs, leading to an increase in nuclear permeability and the leaking of cytoplasmic proteins into the nucleus. Our finding that nuclear “leakiness” is dramatically accelerated during aging and that a subset of nucleoporins is oxidatively damaged in old cells suggests that the accumulation of damage at the NPC might be a crucial aging event. AU - D'Angelo, Maximiliano A. AU - Raices, Marcela AU - Panowski, Siler H. AU - HETZER, Martin W ID - 11108 IS - 2 JF - Cell KW - General Biochemistry KW - Genetics and Molecular Biology SN - 0092-8674 TI - Age-dependent deterioration of nuclear pore complexes causes a loss of nuclear integrity in postmitotic cells VL - 136 ER - TY - JOUR AB - Gradients of axon guidance molecules instruct the formation of continuous neural maps, such as the retinotopic map in the vertebrate visual system. Here we show that molecular gradients can also instruct the formation of a discrete neural map. In the fly olfactory system, axons of 50 classes of olfactory receptor neurons (ORNs) and dendrites of 50 classes of projection neurons (PNs) form one-to-one connections at discrete units called glomeruli. We provide expression, loss- and gain-of-function data to demonstrate that the levels of transmembrane Semaphorin-1a (Sema-1a), acting cell-autonomously as a receptor or part of a receptor complex, direct the dendritic targeting of PNs along the dorsolateral to ventromedial axis of the antennal lobe. Sema-1a also regulates PN axon targeting in higher olfactory centers. Thus, graded expression of Sema-1a contributes to connection specificity from ORNs to PNs and then to higher brain centers, ensuring proper representation of olfactory information in the brain. AU - Komiyama, Takaki AU - Sweeney, Lora Beatrice Jaeger AU - Schuldiner, Oren AU - Garcia, K. Christopher AU - Luo, Liqun ID - 7704 IS - 2 JF - Cell SN - 0092-8674 TI - Graded expression of semaphorin-1a cell-autonomously directs dendritic targeting of olfactory projection neurons VL - 128 ER - TY - JOUR AB - Nuclear pore complexes (NPCs) are large multiprotein assemblies that allow traffic between the cytoplasm and the nucleus. During mitosis in higher eukaryotes, the Nuclear Envelope (NE) breaks down and NPCs disassemble. How NPCs reassemble and incorporate into the NE upon mitotic exit is poorly understood. We demonstrate a function for the conserved Nup107-160 complex in this process. Partial in vivo depletion of Nup133 or Nup107 via RNAi in HeLa cells resulted in reduced levels of multiple nucleoporins and decreased NPC density in the NE. Immunodepletion of the entire Nup107-160 complex from in vitro nuclear assembly reactions produced nuclei with a continuous NE but no NPCs. This phenotype was reversible only if Nup107-160 complex was readded before closed NE formation. Depletion also prevented association of FG-repeat nucleoporins with chromatin. We propose a stepwise model in which postmitotic NPC assembly initiates on chromatin via early recruitment of the Nup107-160 complex. AU - Walther, Tobias C. AU - Alves, Annabelle AU - Pickersgill, Helen AU - Loı̈odice, Isabelle AU - HETZER, Martin W AU - Galy, Vincent AU - Hülsmann, Bastian B. AU - Köcher, Thomas AU - Wilm, Matthias AU - Allen, Terry AU - Mattaj, Iain W. AU - Doye, Valérie ID - 11122 IS - 2 JF - Cell KW - General Biochemistry KW - Genetics and Molecular Biology SN - 0092-8674 TI - The conserved Nup107-160 complex is critical for nuclear pore complex assembly VL - 113 ER - TY - JOUR AB - In contrast to animals, little is known about pattern formation in plants. Physiological and genetic data suggest the involvement of the phytohormone auxin in this process. Here, we characterize a novel member of the PIN family of putative auxin efflux carriers, Arabidopsis PIN4, that is localized in developing and mature root meristems. Atpin4 mutants are defective in establishment and maintenance of endogenous auxin gradients, fail to canalize externally applied auxin, and display various patterning defects in both embryonic and seedling roots. We propose a role for AtPIN4 in generating a sink for auxin below the quiescent center of the root meristem that is essential for auxin distribution and patterning. AU - Friml, Jirí AU - Benková, Eva AU - Blilou, Ikram AU - Wiśniewska, Justyna AU - Hamann, Thorsten AU - Ljung, Karin AU - Woody, Scott AU - Sandberg, Göran AU - Scheres, Ben AU - Jürgens, Gerd AU - Palme, Klaus ID - 2989 IS - 5 JF - Cell SN - 0092-8674 TI - AtPIN4 mediates sink-driven auxin gradients and root patterning in Arabidopsis VL - 108 ER - TY - JOUR AB - The role of inhibitory Golgi cells in cerebellar function was investigated by selectively ablating Golgi cells expressing human interleukin-2 receptor α subunit in transgenic mice, using the immunotoxin- mediated cell targeting technique. Golgi cell disruption caused severe acute motor disorders. These mice showed gradual recovery but retained a continuing inability to perform compound movements. Optical and electrical recordings combined with immunocytological analysis indicated that elimination of Golgi cells not only reduces GABA-mediated inhibition but also attenuates functional NMDA receptors in granule cells. These results demonstrate that synaptic integration involving both GABA inhibition and NMDA receptor activation is essential for compound motor coordination. Furthermore, this integration can adapt after Golgi cell elimination so as not to evoke overexcitation by the reduction of NMDA receptors. AU - Watanabe, Dai AU - Inokawa, Hitoshi AU - Hashimoto, Kouichi AU - Suzuki, Noboru AU - Kano, Masanobu AU - Shigemoto, Ryuichi AU - Hirano, Tomoo AU - Toyama, Keisuke AU - Kaneko, Satoshi AU - Yokoi, Mineto AU - Moriyoshi, Koki AU - Suzuki, Misao AU - Kobayashi, Kazuto AU - Nagatsu, Toshiharu AU - Kreitman, Robert AU - Pastan, Ira AU - Nakanishi, Shigetada ID - 2586 IS - 1 JF - Cell SN - 0092-8674 TI - Ablation of cerebellar Golgi cells disrupts synaptic integration involving GABA inhibition and NMDA receptor activation in motor coordination VL - 95 ER - TY - JOUR AB - Natural isolates of C. elegans exhibit either solitary or social feeding behavior. Solitary foragers move slowly on a bacterial lawn and disperse across it, while social foragers move rapidly on bacteria and aggregate together. A loss-of-function mutation in the npr-1 gene, which encodes a predicted G protein–coupled receptor similar to neuropeptide Y receptors, causes a solitary strain to take on social behavior. Two isoforms of NPR-1 that differ at a single residue occur in the wild. One isoform, NPR-1 215F, is found exclusively in social strains, while the other isoform, NPR-1 215V, is found exclusively in solitary strains. An NPR-1 215V transgene can induce solitary feeding behavior in a wild social strain. Thus, isoforms of a putative neuropeptide receptor generate natural variation in C. elegans feeding behavior. AU - de Bono, Mario AU - Bargmann, Cornelia I ID - 6160 IS - 5 JF - Cell SN - 0092-8674 TI - Natural variation in a neuropeptide Y receptor homolog modifies social behavior and food response in C. elegans VL - 94 ER - TY - JOUR AB - Taking advantage of the restricted expression of metabotropic glutamate receptor subtype 6 (mGIuR6) in retinal ON bipolar cells, we generated knockout mice lacking mGIuR6 expression. The homozygous mutant mice showed a loss of ON responses but unchanged OFF responses to light. The mutant mice displayed no obvious changes in retinal cell organization nor in the projection of optic fibers to the brain. Furthermore, the mGIuR6-deficient mice showed visual behavioral responses to light stimulation as examined by shuttle box avoidance behavior experiments using light exposure as a conditioned stimulus. The results demonstrate that mGIuR6 is essential in synaptic transmission to the ON bipolar cell and that the OFF response provides an important means for transmitting visual information. AU - Masu, Masayuki AU - Iwakabe, Hideki AU - Tagawa, Yoshiaki AU - Miyoshi, Tomomitsu AU - Yamashita, Masayuki AU - Fukuda, Yutaka AU - Sasaki, Hitoshi AU - Hiroi, Kano AU - Nakamura, Yasuhisa AU - Shigemoto, Ryuichi AU - Takada, Masahiko AU - Nakamura, Kenji AU - Nakao, Kazuki AU - Katsuki, Motoya AU - Nakanishi, Shigetada ID - 2559 IS - 5 JF - Cell SN - 0092-8674 TI - Specific deficit of the ON response in visual transmission by targeted disruption of the mGIuR6 gene VL - 80 ER - TY - JOUR AB - The retinal bipolar cell receiving glutamate transmission from photoreceptors mediates a key process in segregating visual signals into ON center and OFF center pathways. This transmission involves a G protein- coupled metabotropic glutamate receptor (mGluR). Immunocytochemical and immunoelectron microscopic studies indicate the restricted localization of a specific mGluR subtype, mGluR6, at the postsynaptic site of the rat rod bipolar cell. This specialization is developmentally regulated: mGluR6 is initially distributed in both the soma and dendrites and is finally concentrated on the postsynaptic site. The mGluR6 localization is reversed when photoreceptors degenerate in the mutant rat with retinal dystrophy. Evidence is thus presented indicating specialized, developmentally regulated receptor distribution in the central nervous system and the crucial role of mGluR6 in photoreceptor-bipolar cell synaptic transmission. AU - Nomura, Akinori AU - Shigemoto, Ryuichi AU - Nakamura, Yasuhisa AU - Okamoto, Naoyuki AU - Mizuno, Noboru AU - Nakanishi, Shigetada ID - 2554 IS - 3 JF - Cell SN - 0092-8674 TI - Developmentally regulated postsynaptic localization of a metabotropic glutamate receptor in rat rod bipolar cells VL - 77 ER -