The maternal NF-kappaB/dorsal gradient of Tribolium castaneum: dynamics of early dorsoventral patterning in a short-germ beetle

Development ◽  
2000 ◽  
Vol 127 (23) ◽  
pp. 5145-5156 ◽  
Author(s):  
G. Chen ◽  
K. Handel ◽  
S. Roth
Keyword(s):  
Tribolium Castaneum ◽  
Cell Layer ◽  
Feedback Regulation ◽  
Growth Zone ◽  
Receptor Activation ◽  
Nuclear Accumulation ◽  
Dorsoventral Patterning ◽  
Posterior Growth Zone ◽  
Toll Receptor ◽  
Nf Kappab

In the long-germ insect Drosophila melanogaster dorsoventral polarity is induced by localized Toll-receptor activation which leads to the formation of a nuclear gradient of the rel/ NF-kappaB protein Dorsal. Peak levels of nuclear Dorsal are found in a ventral stripe spanning the entire length of the blastoderm embryo allowing all segments and their dorsoventral subdivisions to be synchronously specified before gastrulation. We show that a nuclear Dorsal protein gradient of similar anteroposterior extension exists in the short-germ beetle, Tribolium castaneum, which forms most segments from a posterior growth zone after gastrulation. In contrast to Drosophila, (i) nuclear accumulation is first uniform and then becomes progressively restricted to a narrow ventral stripe, (ii) gradient refinement is accompanied by changes in the zygotic expression of the Tribolium Toll-receptor suggesting feedback regulation and, (iii) the gradient only transiently overlaps with the expression of a potential target, the Tribolium twist homolog, and does not repress Tribolium decapentaplegic. No nuclear Dorsal is seen in the cells of the growth zone of Tribolium embryos, indicating that here dorsoventral patterning occurs by a different mechanism. However, Dorsal is up-regulated and transiently forms a nuclear gradient in the serosa, a protective extraembryonic cell layer ultimately covering the whole embryo.

scholarly journals TheDrosophila double-timeSMutation Delays the Nuclear Accumulation ofperiodProtein and Affects the Feedback Regulation ofperiodmRNA

2001 ◽  
Vol 21 (18) ◽  
pp. 7117-7126 ◽  
Author(s):  
Shu Bao ◽  
Jason Rihel ◽  
Ed Bjes ◽  
Jin-Yuan Fan ◽  
Jeffrey L. Price
Keyword(s):  
Feedback Regulation ◽  
Nuclear Accumulation

Expression pattern ofBrachyuryin the molluscPatella vulgatasuggests a conserved role in the establishment of the AP axis in Bilateria

Development ◽  
2002 ◽  
Vol 129 (6) ◽  
pp. 1411-1421 ◽  
Author(s):  
Nicolas Lartillot ◽  
Olivier Lespinet ◽  
Michel Vervoort ◽  
André Adoutte
Keyword(s):  
Expression Pattern ◽  
Bilateral Symmetry ◽  
Growth Zone ◽  
Posterior Pole ◽  
Axis Formation ◽  
Posterior Edge ◽  
Cell Stage ◽  
Posterior Growth Zone ◽  
Erk Activity ◽  
Anterior Posterior

We report the characterisation of a Brachyury ortholog (PvuBra) in the marine gastropod Patella vulgata. In this mollusc, the embryo displays an equal cleavage pattern until the 32-cell stage. There, an inductive event takes place that sets up the bilateral symmetry, by specifying one of the four initially equipotent vegetal macromeres as the posterior pole of all subsequent morphogenesis. This macromere, usually designated as 3D, will subsequently act as an organiser. We show that 3D expresses PvuBra as soon as its fate is determined. As reported for another mollusc (J. D. Lambert and L. M. Nagy (2001) Development128, 45-56), we found that 3D determination and activity also involve the activation of the MAP kinase ERK, and we further show that PvuBra expression in 3D requires ERK activity. PvuBra expression then rapidly spreads to neighbouring cells that cleave in a bilateral fashion and whose progeny will constitute the posterior edge of the blastopore during gastrulation, suggesting a role for PvuBra in regulating cell movements and cleavage morphology in Patella. Until the completion of gastrulation, PvuBra expression is maintained at the posterior pole, and along the developing anterior-posterior axis. Comparing this expression pattern with what is known in other Bilateria, we advocate that Brachyury might have a conserved role in the regulation of anterior-posterior patterning among Bilateria, through the maintenance of a posterior growth zone, suggesting that a teloblastic mode of axis formation might be ancestral to the Bilateria.

scholarly journals Concerted involvement of Cdx/Hox genes and Wnt signaling in morphogenesis of the caudal neural tube and cloacal derivatives from the posterior growth zone

Development ◽  
2011 ◽  
Vol 138 (17) ◽  
pp. 3859-3859 ◽  
Author(s):  
C. van de Ven ◽  
M. Bialecka ◽  
R. Neijts ◽  
T. Young ◽  
J. E. Rowland ◽  
...  
Keyword(s):  
Wnt Signaling ◽  
Neural Tube ◽  
Hox Genes ◽  
Growth Zone ◽  
Posterior Growth Zone

scholarly journals Dysregulated Inflammatory Signaling upon Charcot-Marie-Tooth Type 1C Mutation of SIMPLE Protein

2015 ◽  
Vol 35 (14) ◽  
pp. 2464-2478 ◽  
Author(s):  
Wenjing Li ◽  
Hong Zhu ◽  
Xuelian Zhao ◽  
Deborah Brancho ◽  
Yuanxin Liang ◽  
...  
Keyword(s):  
Transforming Growth Factor ◽  
Signal Propagation ◽  
Transforming Growth Factor Β ◽  
Receptor Activation ◽  
Nuclear Accumulation ◽  
Endosomal Trafficking ◽  
Inflammatory Signaling ◽  
Charcot Marie Tooth ◽  
Late Endosomes ◽  
Tooth Type

Endosomal trafficking is a key mechanism to modulate signal propagation and cross talk. Ubiquitin adaptors, along withendosomalsortingcomplexrequired fortransport (ESCRT) complexes, are also integrated to terminate ligand-receptor activation in late endosomes and multivesicular bodies (MVBs). Within these pathways, we recently demonstrated that the protein SIMPLE is a novel player in MVB regulation. SIMPLE is also clinically important and its mutation accounts for the Charcot-Marie-Tooth type 1C (CMT1C) disease. MVB defects of mutation and deletion of SIMPLE, however, are distinct. Here, we show that MVB defects found in mutation but not deletion of SIMPLE lead to impaired turnover and accumulation of ESCRT-0 protein Hrs puncta in late endosomes. We further uncover increased colocalization of ubiquitin ligase TRAF6 and Hrs in late endosomes. Upon stimulation with interkeukin-1 or transforming growth factor β, prolonged activation of p38 kinase/JNK is detected, while nuclear accumulation of NF-κB and phosphorylation of SMAD2 is reduced with CMT1C mutation. The aberrant kinetics we observed in inflammatory signaling may contribute to increased tumor susceptibility and changes in the levels of chemokines/cytokines that result from CMT1C mutation. We propose that altered endosomal trafficking due to malformations of MVBs and subsequent atypical signaling kinetic may account for a toxic gain of function in CMT1C pathogenesis.

scholarly journals Anamorphic development and extended parental care in a 520 million-year-old stem-group euarthropod from China

2018 ◽  
Author(s):  
Dongjing Fu ◽  
Javier Ortega-Hernández ◽  
Allison C. Daley ◽  
Xingliang Zhang ◽  
Degan Shu
Keyword(s):  
Parental Care ◽  
Fossil Record ◽  
Growth Zone ◽  
Posterior Growth Zone ◽  
Stem Group ◽  
History Of ◽  
Sexually Mature ◽  
Chengjiang Lagerstätte ◽  
Extended Parental Care ◽  
Anamorphic Development

AbstractExtended parental care (XPC) is a complex reproductive strategy in which progenitors actively look after their offspring up to – or beyond – the first juvenile stage in order to maximize their fitness. Although the euarthropod fossil record has produced several examples of brood-care, the appearance of XPC within this phylum remains poorly constrained given the scarcity of developmental data for Palaeozoic stem-group representatives that would link juvenile and adult forms in an ontogenetic sequence. Here, we describe the post-embryonic growth of Fuxianhuia protensa from the early Cambrian Chengjiang Lagerstätte, and show parental care in this stem-group euarthropod. We recognize fifteen distinct ontogenetic stages based on the number and shape of the trunk tergites, and their allocation between the morphologically distinct thorax and abdomen. Our data demonstrate anamorphic post-embryonic development in F. protensa, in which tergites were sequentially added from a posterior growth zone. A life assemblage consisting of a sexually mature F. protensa adult alongside four ontogenetically coeval juveniles, constitutes the oldest occurrence of XPC in the panarthropod fossil record. These findings provide the most phylogenetically basal evidence of anamorphosis in the evolutionary history of total-group Euarthropoda, and reveal a complex post-embryonic reproductive ecology for its early representatives.

scholarly journals Linear signaling in the Toll-Dorsal pathway of Drosophila: activated Pelle kinase specifies all threshold outputs of gene expression while the bHLH protein Twist specifies a subset

Development ◽  
2002 ◽  
Vol 129 (14) ◽  
pp. 3411-3419 ◽  
Author(s):  
Angelike Stathopoulos ◽  
Michael Levine
Keyword(s):  
Target Genes ◽  
Early Gene ◽  
Bhlh Protein ◽  
Bhlh Transcription Factor ◽  
Gradient System ◽  
Dorsoventral Patterning ◽  
Helix Loop Helix ◽  
Dorsal Pathway ◽  
Toll Signaling ◽  
Toll Receptor

Differential activation of the Toll receptor leads to the formation of a broad Dorsal nuclear gradient that specifies at least three patterning thresholds of gene activity along the dorsoventral axis of precellular embryos. We investigate the activities of the Pelle kinase and Twist basic helix-loop-helix (bHLH) transcription factor in transducing Toll signaling. Pelle functions downstream of Toll to release Dorsal from the Cactus inhibitor. Twist is an immediate-early gene that is activated upon entry of Dorsal into nuclei. Transgenes misexpressing Pelle and Twist were introduced into different mutant backgrounds and the patterning activities were visualized using various target genes that respond to different thresholds of Toll-Dorsal signaling. These studies suggest that an anteroposterior gradient of Pelle kinase activity is sufficient to generate all known Toll-Dorsal patterning thresholds and that Twist can function as a gradient morphogen to establish at least two distinct dorsoventral patterning thresholds. We discuss how the Dorsal gradient system can be modified during metazoan evolution and conclude that Dorsal-Twist interactions are distinct from the interplay between Bicoid and Hunchback, which pattern the anteroposterior axis.

Nuclear export signal of IkappaBalpha interferes with the Rev-dependent posttranscriptional regulation of human immunodeficiency virus type I

1997 ◽  
Vol 110 (22) ◽  
pp. 2883-2893
Author(s):  
F. Bachelerie ◽  
M.S. Rodriguez ◽  
C. Dargemont ◽  
D. Rousset ◽  
D. Thomas ◽  
...  
Keyword(s):  
Dna Binding ◽  
Nuclear Export ◽  
Nuclear Export Signal ◽  
Binding Activity ◽  
Nuclear Accumulation ◽  
Viral Rnas ◽  
Dna Binding Activity ◽  
Nf Kappab ◽  
Export Signal ◽  
Hiv 1

De novo synthesized IkappaBalpha accumulates transiently in the nucleus where it inhibits NF-kappaB-dependent transcription and reduces nuclear NF-kappaB content. A sequence present in the C-terminal domain of IkappaBalpha and homologous to the HIV-1 Rev nuclear export signal (NES) has been recently defined as a functional NES conferring on IkappaBalpha the ability to export IkappaBalpha/NF-kappaB complexes. Rev utilises its RNA-binding activity and NES sequence to promote specifically the transport of unspliced and monospliced viral RNAs to the cytoplasm. The object of this work was to determine if nuclear IkappaBalpha could interfere with Rev-dependent transport of viral RNA from the nucleus to the cytoplasm. We report that accumulation of IkappaBalpha in the cell nucleus blocks viral replication. This effect could be dissociated from the capacity of IkappaBalpha to inhibit NF-kappaB-DNA-binding activity and required a functional IkappaBalpha NES motif. Indeed, mutation of the NES abrogated the capacity of IkappaBalpha to inhibit Rev-dependent mechanisms involved in the replication of either wild-type or NF-kappaB-mutated HIV-1 molecular clones. Nuclear accumulation of a reporter protein tagged with a nuclear localization signal (NLS) and fused to the IkappaBalpha NES motif (NLS-PK-NES) was sufficient to inhibit HIV-1 replication at a post-transcriptional level by specifically blocking the expression of a Rev-dependent gene. Furthermore, in cells pulsed with TNF, a treatment which favors nuclear accumulation of newly synthesized IkappaBalpha, NLS-PK-NES expression promoted sustained accumulation of nuclear NF-kappaB lacking DNA-binding activity. This NES-mediated accumulation of inactive nuclear NF-kappaB is likely the consequence of interference in the IkappaBalpha-mediated export of NF-kappaB. These findings indicate that IkappaBalpha and Rev compete for the same nuclear export pathway and suggest that nuclear accumulation of IkappaBalpha, which would occur during normal physiological cell activation process, may interfere with the Rev-NES-mediated export pathway of viral RNAs, thus inhibiting HIV-1 replication.

Phosphorylation modulates direct interactions between the Toll receptor, Pelle kinase and Tube

Development ◽  
1998 ◽  
Vol 125 (23) ◽  
pp. 4719-4728
Author(s):  
B. Shen ◽  
J.L. Manley
Keyword(s):  
Transcription Factor ◽  
Protein Kinase ◽  
Signaling Cascade ◽  
Death Domain ◽  
C Terminus ◽  
Evolutionarily Conserved ◽  
Toll Receptor ◽  
Inhibitory Domain ◽  
Nf Kappab

Determination of dorsal/ventral polarity in Drosophila requires 12 genetically defined, maternally encoded proteins. These include Toll, a transmembrane receptor, Pelle, a ser/thr protein kinase and Tube, all of which function intracytoplasmically to initiate the cascade that ultimately activates Dorsal, an NF-kappaB family transcription factor. Here we describe biochemical interactions between recombinant Toll, Pelle and Tube that provide insights into early events in activation of the signaling cascade. We first show that Pelle binds directly to a region within the Toll intracytoplasmic domain, providing the first evidence that these two evolutionarily conserved molecules physically interact. We then demonstrate that Pelle can be autophosphorylated, and that this prevents binding to Toll as well as Tube. Autophosphorylation occurs in the N-terminal, death-domain-containing region of Pelle, which is dispensable for binding to Toll but required for enzymatic activity. We also show that Pelle phosphorylates Toll, within the region required for Pelle interaction, but this phosphorylation can be blocked by a previously characterized inhibitory domain at the Toll C terminus. These and other results allow us to propose a model by which multiple phosphorylation-regulated interactions between these three proteins lead to activation of the Dorsal signaling pathway.

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