scholarly journals Revealing RCOR2 as a regulatory component of nuclear speckles

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Carlos Rivera ◽  
Daniel Verbel-Vergara ◽  
Duxan Arancibia ◽  
Anna Lappala ◽  
Marcela González ◽  
...  

Abstract Background Nuclear processes such as transcription and RNA maturation can be impacted by subnuclear compartmentalization in condensates and nuclear bodies. Here, we characterize the nature of nuclear granules formed by REST corepressor 2 (RCOR2), a nuclear protein essential for pluripotency maintenance and central nervous system development. Results Using biochemical approaches and high-resolution microscopy, we reveal that RCOR2 is localized in nuclear speckles across multiple cell types, including neurons in the brain. RCOR2 forms complexes with nuclear speckle components such as SON, SRSF7, and SRRM2. When cells are exposed to chemical stress, RCOR2 behaves as a core component of the nuclear speckle and is stabilized by RNA. In turn, nuclear speckle morphology appears to depend on RCOR2. Specifically, RCOR2 knockdown results larger nuclear speckles, whereas overexpressing RCOR2 leads to smaller and rounder nuclear speckles. Conclusion Our study suggests that RCOR2 is a regulatory component of the nuclear speckle bodies, setting this co-repressor protein as a factor that controls nuclear speckles behavior.

2021 ◽  
Author(s):  
Carlos Rivera ◽  
Daniel Verbel ◽  
Duxan Arancibia ◽  
Anna Lappala ◽  
Marcela González ◽  
...  

Abstract Background Nuclear processes such as transcription and RNA maturation can be impacted by subnuclear compartmentalization in condensates and nuclear bodies. Here we characterize the nature of nuclear granules formed by REST corepressor 2 (RCOR2), a nuclear protein essential for pluripotency maintenance and central nervous system development. Results Using biochemical approaches and high-resolution microscopy, we reveal that RCOR2 is localized in nuclear speckles across multiple cell types, including neurons in the brain. RCOR2 forms complexes with nuclear speckle components such as SON, SRSF7, and SRRM2. When cells are exposed to chemical stress, RCOR2 behaves as a core component of the nuclear speckle and is stabilized by RNA. In turn, nuclear speckle morphology appears to depend on RCOR2. Specifically, RCOR2 knockdown results larger nuclear speckles, whereas overexpressing RCOR2 leads to smaller and rounder nuclear speckles. Conclusion Our study suggests that RCOR2 is a regulatory component of the nuclear speckle bodies, setting this co-repressor protein as a factor that controls nuclear speckles behavior.


2021 ◽  
Vol 22 (11) ◽  
pp. 5793
Author(s):  
Brianna M. Quinville ◽  
Natalie M. Deschenes ◽  
Alex E. Ryckman ◽  
Jagdeep S. Walia

Sphingolipids are a specialized group of lipids essential to the composition of the plasma membrane of many cell types; however, they are primarily localized within the nervous system. The amphipathic properties of sphingolipids enable their participation in a variety of intricate metabolic pathways. Sphingoid bases are the building blocks for all sphingolipid derivatives, comprising a complex class of lipids. The biosynthesis and catabolism of these lipids play an integral role in small- and large-scale body functions, including participation in membrane domains and signalling; cell proliferation, death, migration, and invasiveness; inflammation; and central nervous system development. Recently, sphingolipids have become the focus of several fields of research in the medical and biological sciences, as these bioactive lipids have been identified as potent signalling and messenger molecules. Sphingolipids are now being exploited as therapeutic targets for several pathologies. Here we present a comprehensive review of the structure and metabolism of sphingolipids and their many functional roles within the cell. In addition, we highlight the role of sphingolipids in several pathologies, including inflammatory disease, cystic fibrosis, cancer, Alzheimer’s and Parkinson’s disease, and lysosomal storage disorders.


2021 ◽  
Vol 15 ◽  
Author(s):  
Louis-Philippe Bernier ◽  
Clément Brunner ◽  
Azzurra Cottarelli ◽  
Matilde Balbi

The neurovascular unit (NVU) of the brain is composed of multiple cell types that act synergistically to modify blood flow to locally match the energy demand of neural activity, as well as to maintain the integrity of the blood-brain barrier (BBB). It is becoming increasingly recognized that the functional specialization, as well as the cellular composition of the NVU varies spatially. This heterogeneity is encountered as variations in vascular and perivascular cells along the arteriole-capillary-venule axis, as well as through differences in NVU composition throughout anatomical regions of the brain. Given the wide variations in metabolic demands between brain regions, especially those of gray vs. white matter, the spatial heterogeneity of the NVU is critical to brain function. Here we review recent evidence demonstrating regional specialization of the NVU between brain regions, by focusing on the heterogeneity of its individual cellular components and briefly discussing novel approaches to investigate NVU diversity.


Development ◽  
2001 ◽  
Vol 128 (5) ◽  
pp. 711-722 ◽  
Author(s):  
T.E. Rusten ◽  
R. Cantera ◽  
J. Urban ◽  
G. Technau ◽  
F.C. Kafatos ◽  
...  

Genes of the spalt family encode nuclear zinc finger proteins. In Drosophila melanogaster, they are necessary for the establishment of head/trunk identity, correct tracheal migration and patterning of the wing imaginal disc. Spalt proteins display a predominant pattern of expression in the nervous system, not only in Drosophila but also in species of fish, mouse, frog and human, suggesting an evolutionarily conserved role for these proteins in nervous system development. Here we show that Spalt works as a cell fate switch between two EGFR-induced cell types, the oenocytes and the precursors of the pentascolopodial organ in the embryonic peripheral nervous system. We show that removal of spalt increases the number of scolopodia, as a result of extra secondary recruitment of precursor cells at the expense of the oenocytes. In addition, the absence of spalt causes defects in the normal migration of the pentascolopodial organ. The dual function of spalt in the development of this organ, recruitment of precursors and migration, is reminiscent of its role in tracheal formation and of the role of a spalt homologue, sem-4, in the Caenorhabditis elegans nervous system.


1997 ◽  
Vol 136 (5) ◽  
pp. 1081-1090 ◽  
Author(s):  
Andrea J. Pereira ◽  
Brian Dalby ◽  
Russell J. Stewart ◽  
Stephen J. Doxsey ◽  
Lawrence S.B. Goldstein

The kinesin superfamily is a large group of proteins (kinesin-like proteins [KLPs]) that share sequence similarity with the microtubule (MT) motor kinesin. Several members of this superfamily have been implicated in various stages of mitosis and meiosis. Here we report our studies on KLP67A of Drosophila. DNA sequence analysis of KLP67A predicts an MT motor protein with an amino-terminal motor domain. To prove this directly, KLP67A expressed in Escherichia coli was shown in an in vitro motility assay to move MTs in the plus direction. We also report expression analyses at both the mRNA and protein level, which implicate KLP67A in the localization of mitochondria in undifferentiated cell types. In situ hybridization studies of the KLP67A mRNA during embryogenesis and larval central nervous system development indicate a proliferation-specific expression pattern. Furthermore, when affinity-purified anti-KLP67A antisera are used to stain blastoderm embryos, mitochondria in the region of the spindle asters are labeled. These data suggest that KLP67A is a mitotic motor of Drosophila that may have the unique role of positioning mitochondria near the spindle.


2010 ◽  
Vol 338 (1) ◽  
pp. 50-62 ◽  
Author(s):  
Yoni E. Gutkovich ◽  
Rachel Ofir ◽  
Yaniv M. Elkouby ◽  
Charna Dibner ◽  
Aharon Gefen ◽  
...  

2020 ◽  
Author(s):  
Doris Voina ◽  
Stefano Recanatesi ◽  
Brian Hu ◽  
Eric Shea-Brown ◽  
Stefan Mihalas

AbstractAs animals adapt to their environments, their brains are tasked with processing stimuli in different sensory contexts. Whether these computations are context dependent or independent, they are all implemented in the same neural tissue. A crucial question is what neural architectures can respond flexibly to a range of stimulus conditions and switch between them. This is a particular case of flexible architecture that permits multiple related computations within a single circuit.Here, we address this question in the specific case of the visual system circuitry, focusing on context integration, defined as the integration of feedforward and surround information across visual space. We show that a biologically inspired microcircuit with multiple inhibitory cell types can switch between visual processing of the static context and the moving context. In our model, the VIP population acts as the switch and modulates the visual circuit through a disinhibitory motif. Moreover, the VIP population is efficient, requiring only a relatively small number of neurons to switch contexts. This circuit eliminates noise in videos by using appropriate lateral connections for contextual spatio-temporal surround modulation, having superior denoising performance compared to circuits where only one context is learned. Our findings shed light on a minimally complex architecture that is capable of switching between two naturalistic contexts using few switching units.Author SummaryThe brain processes information at all times and much of that information is context-dependent. The visual system presents an important example: processing is ongoing, but the context changes dramatically when an animal is still vs. running. How is context-dependent information processing achieved? We take inspiration from recent neurophysiology studies on the role of distinct cell types in primary visual cortex (V1).We find that relatively few “switching units” — akin to the VIP neuron type in V1 in that they turn on and off in the running vs. still context and have connections to and from the main population — is sufficient to drive context dependent image processing. We demonstrate this in a model of feature integration, and in a test of image denoising. The underlying circuit architecture illustrates a concrete computational role for the multiple cell types under increasing study across the brain, and may inspire more flexible neurally inspired computing architectures.


2017 ◽  
Author(s):  
Jonathan Enriquez ◽  
Laura Quintana Rio ◽  
Richard Blazeski ◽  
Carol Mason ◽  
Richard S. Mann

SummaryIn both vertebrates and invertebrates, neurons and glia are generated in a stereotyped order from dedicated progenitors called neural stem cells, but the purpose of invariant lineages is not understood. Here we show that three of the stem cells that produce leg motor neurons in Drosophila also generate a specialized subset of glia, the neuropil glia, which wrap and send processes into the neuropil where motor neuron dendrites arborize. The development of the neuropil glia and leg motor neurons is highly coordinated. However, although individual motor neurons have a stereotyped birth order and transcription factor code, both the number and individual morphologies of the glia born from these lineages are highly plastic, even though the final structure they contribute to is highly stereotyped. We suggest that the shared lineages of these two cell types facilitates the assembly of complex neural circuits, and that the two different birth order strategies – hardwired for motor neurons and flexible for glia – are important for robust nervous system development and homeostasis.


2021 ◽  
Vol 15 ◽  
Author(s):  
Rachel A. Keuls ◽  
Ronald J. Parchem

Neural crest development involves a series of dynamic, carefully coordinated events that result in human disease when not properly orchestrated. Cranial neural crest cells acquire unique multipotent developmental potential upon specification to generate a broad variety of cell types. Studies of early mammalian neural crest and nervous system development often use the Cre-loxP system to lineage trace and mark cells for further investigation. Here, we carefully profile the activity of two common neural crest Cre-drivers at the end of neurulation in mice. RNA sequencing of labeled cells at E9.5 reveals that Wnt1-Cre2 marks cells with neuronal characteristics consistent with neuroepithelial expression, whereas Sox10-Cre predominantly labels the migratory neural crest. We used single-cell mRNA and single-cell ATAC sequencing to profile the expression of Wnt1 and Sox10 and identify transcription factors that may regulate the expression of Wnt1-Cre2 in the neuroepithelium and Sox10-Cre in the migratory neural crest. Our data identify cellular heterogeneity during cranial neural crest development and identify specific populations labeled by two Cre-drivers in the developing nervous system.


2018 ◽  
Author(s):  
Jill R. Crittenden ◽  
Efthimios M. C. Skoulakis ◽  
Elliott. S. Goldstein ◽  
Ronald L. Davis

ABSTRACTMEF2 (myocyte enhancer factor 2) transcription factors are found in the brain and muscle of insects and vertebrates and are essential for the differentiation of multiple cell types. We show that in the fruitfly Drosophila, MEF2 is essential for normal development of wing veins, and for mushroom body formation in the brain. In embryos mutant for D-mef2, there was a striking reduction in the number of mushroom body neurons and their axon bundles were not detectable. D-MEF2 expression coincided with the formation of embryonic mushroom bodies and, in larvae, expression onset was confirmed to be in post-mitotic neurons. With a D-mef2 point mutation that disrupts nuclear localization, we find that D-MEF2 is restricted to a subset of Kenyon cells that project to the α/β, and γ axonal lobes of the mushroom bodies, but not to those forming the α’/β’ lobes. Our findings that ancestral mef2 is specifically important in dopamine-receptive neurons has broad implications for its function in mammalian neurocircuits.


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