scholarly journals Centrosome maturation requires phosphorylation-mediated sequential domain interactions of SPD-5

2021 ◽  
Author(s):  
Momoe Nakajo ◽  
Hikaru Kano ◽  
Kenji Tsuyama ◽  
Nami Haruta ◽  
Asako Sugimoto
Keyword(s):  
Direct Interaction ◽  
Scaffold Proteins ◽  
Dependent Manner ◽  
C Elegans ◽  
Evolutionarily Conserved ◽  
Domain Interactions ◽  
Pericentriolar Material ◽  
Centrosomal Proteins ◽  
Pa Domain

Centrosomes consist of two centrioles and surrounding pericentriolar material (PCM). PCM expands during mitosis in a process called centrosome maturation, in which PCM scaffold proteins play pivotal roles to recruit other centrosomal proteins. In C. elegans, the scaffold protein SPD-5 forms PCM scaffold in a PLK-1 phosphorylation-dependent manner. However, how phosphorylation of SPD-5 promotes PCM scaffold assembly is unclear. Here, we identified three functional domains of SPD-5 through in vivo domain analyses, and propose that sequential domain interactions of SPD-5 are required for mitotic PCM scaffold assembly. Firstly, SPD-5 is targeted to centrioles through direct interaction between its centriole localization (CL) domain and a centriolar protein PCMD-1. Then, intra- and inter-molecular interaction between SPD-5 phospho-regulated multimerization (PReM) domain and the PReM association (PA) domain is triggered by phosphorylation by PLK-1, which leads to PCM scaffold expansion. Our findings suggest that the sequential domain interactions of scaffold proteins mediated by Polo/PLK-1 phosphorylation is an evolutionarily conserved mechanism of PCM scaffold assembly.

scholarly journals Lamellipodin and the Scar/WAVE complex cooperate to promote cell migration in vivo

2013 ◽  
Vol 203 (4) ◽  
pp. 673-689 ◽  
Author(s):  
Ah-Lai Law ◽  
Anne Vehlow ◽  
Maria Kotini ◽  
Lauren Dodgson ◽  
Daniel Soong ◽  
...  
Keyword(s):  
Cell Migration ◽  
Neural Crest ◽  
Neural Crest Cell ◽  
Direct Interaction ◽  
Dependent Manner ◽  
Border Cell ◽  
Promote Cell Migration ◽  
Wave Complex

Cell migration is essential for development, but its deregulation causes metastasis. The Scar/WAVE complex is absolutely required for lamellipodia and is a key effector in cell migration, but its regulation in vivo is enigmatic. Lamellipodin (Lpd) controls lamellipodium formation through an unknown mechanism. Here, we report that Lpd directly binds active Rac, which regulates a direct interaction between Lpd and the Scar/WAVE complex via Abi. Consequently, Lpd controls lamellipodium size, cell migration speed, and persistence via Scar/WAVE in vitro. Moreover, Lpd knockout mice display defective pigmentation because fewer migrating neural crest-derived melanoblasts reach their target during development. Consistently, Lpd regulates mesenchymal neural crest cell migration cell autonomously in Xenopus laevis via the Scar/WAVE complex. Further, Lpd’s Drosophila melanogaster orthologue Pico binds Scar, and both regulate collective epithelial border cell migration. Pico also controls directed cell protrusions of border cell clusters in a Scar-dependent manner. Taken together, Lpd is an essential, evolutionary conserved regulator of the Scar/WAVE complex during cell migration in vivo.

scholarly journals Identification of a mouse protein whose homolog in Saccharomyces cerevisiae is a component of the CCR4 transcriptional regulatory complex.

1995 ◽  
Vol 15 (7) ◽  
pp. 3487-3495 ◽  
Author(s):  
M P Draper ◽  
C Salvadore ◽  
C L Denis
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Yeast Cells ◽  
Significant Similarity ◽  
Eukaryotic Transcription ◽  
C Elegans ◽  
Mouse Protein ◽  
Transcriptional Regulatory ◽  
Evolutionarily Conserved ◽  
Regulatory Complex

The CCR4 protein from Saccharomyces cerevisiae is a component of a multisubunit complex that is required for the regulation of a number of genes in yeast cells. We report here the identification of a mouse protein (mCAF1 [mouse CCR4-associated factor 1]) which is capable of interacting with and binding to the yeast CCR4 protein. The mCAF1 protein was shown to have significant similarity to proteins from humans, Caenorhabditis elegans, Arabidopsis thaliana, and S. cerevisiae. The yeast gene (yCAF1) had been previously cloned as the POP2 gene, which is required for expression of several genes. Both yCAF1 (POP2) and the C. elegans homolog of CAF1 were shown to genetically interact with CCR4 in vivo, and yCAF1 (POP2) physically associated with CCR4. Disruption of the CAF1 (POP2) gene in yeast cells gave phenotypes and defects in transcription similar to those observed with disruptions of CCR4, including the ability to suppress spt10-enhanced ADH2 expression. In addition, yCAF1 (POP2) when fused to LexA was capable of activating transcription. mCAF1 could also activate transcription when fused to LexA and could functionally substitute for yCAF1 in allowing ADH2 expression in an spt10 mutant background. These data imply that CAF1 is a component of the CCR4 protein complex and that this complex has retained evolutionarily conserved functions important to eukaryotic transcription.

scholarly journals Mediator complex subunit Med19 binds directly GATA transcription factors and is required with Med1 for GATA-driven gene regulation in vivo

2020 ◽  
Vol 295 (39) ◽  
pp. 13617-13629
Author(s):  
Clément Immarigeon ◽  
Sandra Bernat-Fabre ◽  
Emmanuelle Guillou ◽  
Alexis Verger ◽  
Elodie Prince ◽  
...  
Keyword(s):  
Transcription Factors ◽  
Target Genes ◽  
Direct Interaction ◽  
Mediator Complex ◽  
Loss Of Function ◽  
Transcriptional Responses ◽  
Rna Pol Ii ◽  
Evolutionarily Conserved

The evolutionarily conserved multiprotein Mediator complex (MED) serves as an interface between DNA-bound transcription factors (TFs) and the RNA Pol II machinery. It has been proposed that each TF interacts with a dedicated MED subunit to induce specific transcriptional responses. But are these binary partnerships sufficient to mediate TF functions? We have previously established that the Med1 Mediator subunit serves as a cofactor of GATA TFs in Drosophila, as shown in mammals. Here, we observe mutant phenotype similarities between another subunit, Med19, and the Drosophila GATA TF Pannier (Pnr), suggesting functional interaction. We further show that Med19 physically interacts with the Drosophila GATA TFs, Pnr and Serpent (Srp), in vivo and in vitro through their conserved C-zinc finger domains. Moreover, Med19 loss of function experiments in vivo or in cellulo indicate that it is required for Pnr- and Srp-dependent gene expression, suggesting general GATA cofactor functions. Interestingly, Med19 but not Med1 is critical for the regulation of all tested GATA target genes, implying shared or differential use of MED subunits by GATAs depending on the target gene. Lastly, we show a direct interaction between Med19 and Med1 by GST pulldown experiments indicating privileged contacts between these two subunits of the MED middle module. Together, these findings identify Med19/Med1 as a composite GATA TF interface and suggest that binary MED subunit–TF partnerships are probably oversimplified models. We propose several mechanisms to account for the transcriptional regulation of GATA-targeted genes.

scholarly journals Eukaryotic initiation factor EIF-3.G augments mRNA translation efficiency to regulate neuronal activity

2021 ◽  
Author(s):  
Stephen M Blazie ◽  
Seika Takayanagi-Kiya ◽  
Katherine A McCulloch ◽  
Yishi Jin
Keyword(s):  
Rna Binding ◽  
Mrna Translation ◽  
Initiation Factor ◽  
Translation Efficiency ◽  
Dependent Manner ◽  
Control Activity ◽  
C Elegans ◽  
Protein Levels ◽  
Neuronal Protein

AbstractThe translation initiation complex eIF3 imparts specialized functions to regulate protein expression. However, understanding of eIF3 activities in neurons remains limited despite widespread dysregulation of eIF3 subunits in neurological disorders. Here, we report a selective role of theC. elegansRNA-binding subunit EIF-3.G in shaping the neuronal protein landscape. We identify a missense mutation in the conserved Zinc-Finger (ZF) of EIF-3.G that acts in a gain-of-function manner to dampen neuronal hyperexcitation. Using neuron type-specific seCLIP, we systematically mapped EIF-3.G-mRNA interactions and identified EIF-3.G occupancy on GC-rich 5′UTRs of a select set of mRNAs enriched in activity-dependent functions. We demonstrate that the ZF mutation in EIF-3.G alters translation in a 5′UTR dependent manner. Our study reveals anin vivomechanism for eIF3 in governing neuronal protein levels to control activity states and offers insights into how eIF3 dysregulation contributes to neuronal disorders.

scholarly journals CFP-1 interacts with HDAC1/2 complexes inC. elegansdevelopment

2018 ◽  
Author(s):  
Bharat Pokhrel ◽  
Yannic Chen ◽  
Jonathan Joseph Biro
Keyword(s):  
Cell Fate ◽  
Embryonic Stem ◽  
Stem Cell Differentiation ◽  
Embryonic Stem Cell Differentiation ◽  
Dependent Manner ◽  
Cell Fate Specification ◽  
C Elegans ◽  
Evolutionarily Conserved ◽  
Epigenetic Regulator ◽  
Inducible Genes

AbstractCFP-1 (CXXC finger binding protein 1) is an evolutionarily conserved protein that binds to non-methylated CpG-rich promoters in humans andC. elegans. This conserved epigenetic regulator is a part of the COMPASS complex that contains the H3K4me3 methyltransferase SET1 in mammals and SET-2 inC. elegans. Previous studies have indicated the importance ofcfp-1in embryonic stem cell differentiation and cell fate specification. However, neither the function nor the mechanism of action ofcfp-1is well understood at the organismal level. To further investigate the function of CFP-1, we have characterisedC. elegansCOMPASS mutantscfp-1(tm6369)andset-2(bn129). We found that bothcfp-1andset-2play an important role in the regulation of fertility and development of the organism. Furthermore, we found that bothcfp-1andset-2are required for H3K4 trimethylation and play a repressive role in the expression of heat shock and salt-inducible genes. Interestingly, we found thatcfp-1but notset-2genetically interacts with Histone Deacetylase (HDAC1/2) complexes to regulate fertility, suggesting a function of CFP-1 outside of the COMPASS complex. Additionally we found thatcfp-1andset-2acts on a separate pathways to regulate fertility and development ofC. elegans. Our results suggest that CFP-1 genetically interacts with HDAC1/2 complexes to regulate fertility, independent of its function within COMPASS complex. We propose that CFP-1 could cooperate with COMPASS complex and/or HDAC1/2 in a context dependent manner.

scholarly journals A novel Netrin-1–sensitive mechanism promotes local SNARE-mediated exocytosis during axon branching

2014 ◽  
Vol 205 (2) ◽  
pp. 217-232 ◽  
Author(s):  
Cortney C. Winkle ◽  
Leslie M. McClain ◽  
Juli G. Valtschanoff ◽  
Charles S. Park ◽  
Christopher Maglione ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Cortical Neurons ◽  
Direct Interaction ◽  
Vesicle Fusion ◽  
Dependent Manner ◽  
Axon Branching ◽  
Spatial Regulation ◽  
Novel Model

Developmental axon branching dramatically increases synaptic capacity and neuronal surface area. Netrin-1 promotes branching and synaptogenesis, but the mechanism by which Netrin-1 stimulates plasma membrane expansion is unknown. We demonstrate that SNARE-mediated exocytosis is a prerequisite for axon branching and identify the E3 ubiquitin ligase TRIM9 as a critical catalytic link between Netrin-1 and exocytic SNARE machinery in murine cortical neurons. TRIM9 ligase activity promotes SNARE-mediated vesicle fusion and axon branching in a Netrin-dependent manner. We identified a direct interaction between TRIM9 and the Netrin-1 receptor DCC as well as a Netrin-1–sensitive interaction between TRIM9 and the SNARE component SNAP25. The interaction with SNAP25 negatively regulates SNARE-mediated exocytosis and axon branching in the absence of Netrin-1. Deletion of TRIM9 elevated exocytosis in vitro and increased axon branching in vitro and in vivo. Our data provide a novel model for the spatial regulation of axon branching by Netrin-1, in which localized plasma membrane expansion occurs via TRIM9-dependent regulation of SNARE-mediated vesicle fusion.

scholarly journals PRIC295, a Nuclear Receptor Coactivator, Identified from PPAR-Interacting Cofactor Complex

PPAR Research ◽  
2010 ◽  
Vol 2010 ◽  
pp. 1-16 ◽  
Author(s):  
Sean R. Pyper ◽  
Navin Viswakarma ◽  
Yuzhi Jia ◽  
Yi-Jun Zhu ◽  
Joseph D. Fondell ◽  
...  
Keyword(s):  
Nuclear Receptor ◽  
Target Genes ◽  
Peroxisome Proliferator ◽  
Dependent Manner ◽  
Peroxisome Proliferator Activated Receptor ◽  
Nuclear Receptor Coactivator ◽  
Evolutionarily Conserved

The peroxisome proliferator-activated receptor- (PPAR) plays a key role in lipid metabolism and energy combustion. Chronic activation of PPAR in rodents leads to the development of hepatocellular carcinomas. The ability of PPAR to induce expression of its target genes depends on Mediator, an evolutionarily conserved complex of cofactors and, in particular, the subunit 1 (Med1) of this complex. Here, we report the identification and characterization of PPAR-interacting cofactor (PRIC)-295 (PRIC295), a novel coactivator protein, and show that it interacts with the Med1 and Med24 subunits of the Mediator complex. PRIC295 contains 10 LXXLL signature motifs that facilitate nuclear receptor binding and interacts with PPAR and five other members of the nuclear receptor superfamily in a ligand-dependent manner. PRIC295 enhances the transactivation function of PPAR, PPAR, and ER. These data demonstrate that PRIC295 interacts with nuclear receptors such as PPAR and functions as a transcription coactivator underin vitroconditions and may play an important role in mediating the effectsin vivoas a member of the PRIC complex with Med1 and Med24.

scholarly journals UNC-16/JIP3 negatively regulates actin dynamics dependent on DLK-1 and microtubule dynamics independent of DLK-1 in regenerating neurons

2018 ◽  
Author(s):  
Sucheta S. Kulkarni ◽  
Vidur Sabharwal ◽  
Seema Sheoran ◽  
Atrayee Basu ◽  
Kunihiro Matsumoto ◽  
...  
Keyword(s):  
Axonal Regeneration ◽  
Microtubule Dynamics ◽  
Growth Potential ◽  
Actin Dynamics ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
C Elegans ◽  
Growth Promoting ◽  
Temporal And Spatial

AbstractNeuronal regeneration after injury depends on the intrinsic growth potential of neurons. UNC-16, a C. elegans JIP3 homologue, inhibits axonal regeneration by regulating regrowth initiation and rate of regrowth. UNC-16/JIP3 inhibits the regeneration promoting activity of DLK-1 long but acts additively to and independently of inhibitory DLK-1 short isoform. UNC-16/JIP3 promotes DLK-1 punctate localization in a concentration dependent manner limiting DLK-1 long availability at the cut site minutes after injury. UNC-16 negatively regulates actin dynamics dependent on DLK-1 and microtubule dynamics independent of DLK-1. The faster regeneration seen in unc-16 does not lead to functional recovery. We propose a model where UNC-16/JIP3 plays its inhibitory role through tight temporal and spatial control of DLK-1 function. The dual inhibitory control by both UNC-16 and DLK-1 short calibrate the intrinsic growth promoting function of DLK-1 long in vivo.

scholarly journals Neurotrophin signaling is modulated by specific transmembrane domain interactions

2021 ◽  
Author(s):  
María L. Franco ◽  
Kirill D. Nadezhdin ◽  
Taylor P. Light ◽  
Sergey A. Goncharuk ◽  
Andrea Soler-Lopez ◽  
...  
Keyword(s):  
Structural Model ◽  
Transmembrane Domain ◽  
Current Model ◽  
Direct Interaction ◽  
Specific Protein ◽  
Dependent Manner ◽  
Protein Interface ◽  
Functional Studies ◽  
Domain Interactions ◽  
Neurotrophin Signaling

The neurotrophin receptors p75 and TrkA play an important role in the development and survival of the nervous system. Biochemical data suggest that p75 and TrkA regulate the activities of each other. For instance, p75 is able to regulate the response of TrkA to lower concentrations of NGF and TrkA promotes p75 shedding by -secretases in a ligand-dependent manner. The current model is that p75 and TrkA are regulated by means of a physical direct interaction, however the nature of such interaction has been elusive so far. Here using NMR in micelles, multiscale molecular dynamics (MD), FRET and functional studies we identified and characterized the direct interaction between TrkA and p75 through the transmembrane domains (TMDs). MD of p75-TMD mutants suggests that although the interaction between TrkA and p75 TMDs is maintained, a specific protein interface is required to facilitate TrkA active homodimerization in the presence of NGF. The same mutations in the TMD protein interface of p75 reduced the activation of TrkA by NGF and cell differentiation. In summary we provide a structural model of the p75/TrkA receptor complex stabilized by transmembrane domain interactions.

scholarly journals An XA21-Associated Kinase (OsSERK2) regulates immunity mediated by the XA21 and XA3 immune receptors

2013 ◽  
Author(s):  
Xuewei Chen ◽  
Shimin Zuo ◽  
Benjamin Schwessinger ◽  
Mawsheng Chern ◽  
Patrick Canlas ◽  
...  
Keyword(s):  
Direct Interaction ◽  
Dependent Manner ◽  
Receptor Kinase ◽  
Immune Receptor ◽  
Immune Receptors ◽  
Yeast Two Hybrid System ◽  
Intracellular Domains ◽  
Activity Dependent

The rice XA21 immune receptor kinase and the structurally related XA3 receptor, confer immunity to Xanthomonas oryzae pv. oryzae (Xoo), the causal agent of bacterial leaf blight. Here we report the isolation of OsSERK2 (rice somatic embryogenesis receptor kinase 2) and demonstrate that OsSERK2 positively regulates immunity mediated by XA21 and XA3 as well as the rice immune receptor FLS2 (OsFLS2). Rice plants silenced for OsSerk2 display altered morphology and reduced sensitivity to the hormone brassinolide. OsSERK2 interacts with the intracellular domains of each immune receptor in the yeast-two-hybrid system in a kinase activity dependent manner. OsSERK2 undergoes bidirectional trans-phosphorylation with XA21 in vitro and forms a constitutive complex with XA21 in vivo. Taken together, these results demonstrate an essential role for OsSERK2 in the function of three rice immune receptors and suggest that direct interaction with the rice immune receptors is critical for their function.

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