scholarly journals Interaction of Infectious Spleen and Kidney Necrosis Virus ORF119L with PINCH Leads to Dominant-Negative Inhibition of Integrin-Linked Kinase and Cardiovascular Defects in Zebrafish

2014 ◽  
Vol 89 (1) ◽  
pp. 763-775 ◽  
Author(s):  
Ji-Min Yuan ◽  
Bai-Liang He ◽  
Lu-Yun Yang ◽  
Chang-Jun Guo ◽  
Shao-Ping Weng ◽  
...  
Keyword(s):  
Dominant Negative ◽  
Zebrafish Embryos ◽  
Mandarin Fish ◽  
Necrosis Virus ◽  
Siniperca Chuatsi ◽  
Content Type ◽  
Dominant Negative Form ◽  
A Genome ◽  
Integrin Linked Kinase ◽  
Negative Form

ABSTRACTInfectious spleen and kidney necrosis virus (ISKNV) is the type species of theMegalocytivirusgenus,Iridoviridaefamily, causing a severe systemic disease with high mortality in mandarin fish (Siniperca chuatsi) in China and Southeast Asia. At present, the pathogenesis of ISKNV infection is still not fully understood. Based on a genome-wide bioinformatics analysis of ISKNV-encoded proteins, we found that ISKNV open reading frame 119L (ORF119L) is predicted to encode a three-ankyrin-repeat (3ANK)-domain-containing protein, which shows high similarity to the dominant negative form of integrin-linked kinase (ILK); i.e., viral ORF119L lacks the ILK kinase domain. Thus, we speculated that viral ORF119L might affect the host ILK complex. Here, we demonstrated that viral ORF119L directly interacts with particularly interesting Cys-His-rich protein (PINCH) and affects the host ILK-PINCH interactionin vitroin fathead minnow (FHM) cells.In vivoORF119L overexpression in zebrafish (Danio rerio) embryos resulted in myocardial dysfunctions with disintegration of the sarcomeric Z disk. Importantly, ORF119L overexpression in zebrafish highly resembles the phenotype of endogenous ILK inhibition, either by overexpressing a dominant negative form of ILK or by injecting an ILK antisense morpholino oligonucleotide. Intriguingly, ISKNV-infected mandarin fish develop disorganized sarcomeric Z disks in cardiomyocytes. Furthermore, phosphorylation of AKT, a downstream effector of ILK, was remarkably decreased in ORF119L-overexpressing zebrafish embryos. With these results, we show that ISKNV ORF119L acts as a domain-negative inhibitor of the host ILK, providing a novel mechanism for the megalocytivirus pathogenesis.IMPORTANCEOur work is the first to show the role of a dominant negative inhibitor of the host ILK from ISKNV (an iridovirus). Mechanistically, the viral ORF119L directly binds to the host PINCH, attenuates the host PINCH-ILK interaction, and thus impairs ILK signaling. Intriguingly, ORF119L-overexpressing zebrafish embryos and ISKNV-infected mandarin fish develop similar disordered sarcomeric Z disks in cardiomyocytes. These findings provide a novel mechanism for megalocytivirus pathogenesis.

scholarly journals Modulation of flight and feeding behaviours requires presynaptic IP3Rs in dopaminergic neurons

eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Anamika Sharma ◽  
Gaiti Hasan
Keyword(s):  
Dopaminergic Neurons ◽  
Calcium Release ◽  
Neural Circuit ◽  
Dominant Negative ◽  
Neuronal Function ◽  
Axonal Projections ◽  
Dominant Negative Form ◽  
Internal States ◽  
Innate Behaviour ◽  
Negative Form

Innate behaviours, although robust and hard wired, rely on modulation of neuronal circuits, for eliciting an appropriate response according to internal states and external cues. Drosophila flight is one such innate behaviour that is modulated by intracellular calcium release through inositol 1,4,5-trisphosphate receptors (IP3Rs). Cellular mechanism(s) by which IP3Rs modulate neuronal function for specific behaviours remain speculative, in vertebrates and invertebrates. To address this, we generated an inducible dominant negative form of the IP3R (IP3RDN). Flies with neuronal expression of IP3RDN exhibit flight deficits. Expression of IP3RDN helped identify key flight-modulating dopaminergic neurons with axonal projections in the mushroom body. Flies with attenuated IP3Rs in these presynaptic dopaminergic neurons exhibit shortened flight bouts and a disinterest in seeking food, accompanied by reduced excitability and dopamine release upon cholinergic stimulation. Our findings suggest that the same neural circuit modulates the drive for food search and for undertaking longer flight bouts.

scholarly journals Suppression of thymic development by the dominant-negative form of Gads

2001 ◽  
Vol 13 (6) ◽  
pp. 777-783 ◽  
Author(s):  
Kazu Kikuchi ◽  
Yoshitada Kawasaki ◽  
Naoto Ishii ◽  
Yoshiteru Sasaki ◽  
Hironobu Asao ◽  
...  
Keyword(s):  
Dominant Negative ◽  
Thymic Development ◽  
Dominant Negative Form ◽  
Negative Form

Wingless blocks bristle formation and morphogenetic furrow progression in the eye through repression of Daughterless

Development ◽  
2002 ◽  
Vol 129 (14) ◽  
pp. 3393-3402 ◽  
Author(s):  
Kenneth M. Cadigan ◽  
Austin D. Jou ◽  
Roel Nusse
Keyword(s):  
Gene Expression ◽  
Ectopic Expression ◽  
Dominant Negative ◽  
Proneural Gene ◽  
Morphogenetic Furrow ◽  
Heterologous Promoter ◽  
Basic Helix Loop Helix ◽  
Helix Loop Helix ◽  
Dominant Negative Form ◽  
Negative Form

In the developing eye, wingless activity represses proneural gene expression (and thus interommatidial bristle formation) and positions the morphogenetic furrow by blocking its initiation in the dorsal and ventral regions of the presumptive eye. We provide evidence that wingless mediates both effects, at least in part, through repression of the basic helix-loop-helix protein Daughterless. daughterless is required for high proneural gene expression and furrow progression. Ectopic expression of wingless blocks Daughterless expression in the proneural clusters. This repression, and that of furrow progression, can be mimicked by an activated form of armadillo and blocked by a dominant negative form of pangolin/TCF. Placing daughterless under the control of a heterologous promoter blocks the ability of ectopic wingless to inhibit bristle formation and furrow progression. hedgehog and decapentapleigic could not rescue the wingless furrow progression block, indicating that wingless acts downstream of these genes. In contrast, Atonal and Scute, which are thought to heterodimerize with Daughterless to promote furrow progression and bristle formation, respectively, can block ectopic wingless action. These results are summarized in a model where daughterless is a major, but probably not the only, target of wingless action in the eye.

FGF signals are involved in the differentiation of notochord cells and mesenchyme cells of the ascidianHalocynthia roretzi

Development ◽  
2001 ◽  
Vol 128 (14) ◽  
pp. 2711-2721 ◽  
Author(s):  
Yoshie Shimauchi ◽  
Seiko D. Murakami ◽  
Nori Satoh
Keyword(s):  
Receptor Gene ◽  
Epidermal Cells ◽  
Dominant Negative ◽  
Tyrosine Kinase Domain ◽  
Fgf Receptor ◽  
Dominant Negative Form ◽  
Notochord Cells ◽  
Mesenchyme Cells ◽  
Endodermal Cells ◽  
Negative Form

Differentiation of notochord cells and mesenchyme cells of the ascidian Halocynthia roretzi requires interactions with neighboring endodermal cells and previous experiments suggest that these interactions require fibroblast growth factor (FGF). In the present study, we examined the role of FGF in these interactions by disrupting signaling using the dominant negative form of the FGF receptor. An FGF receptor gene of H. roretzi (HrFGFR) is expressed both maternally and zygotically. The maternally expressed transcript was ubiquitously distributed in fertilized eggs and in early embryos. Zygotic expression became evident by the neurula stage and transcripts were detected in epidermal cells of the posterior half of embryos. Synthetic mRNA for the dominant negative form of FGFR, in which the intracellular tyrosine kinase domain was deleted, was injected into fertilized eggs to interfere with the possible function of HrFGFR. Injected eggs cleaved and gastrulated the same as the control embryos. Analyses of the expression of differentiation markers in the experimental embryos indicated that the differentiation of epidermal cells, muscle cells and endodermal cells was not affected significantly. However, manipulated embryos showed downregulation of notochord-specific Brachyury expression and failure of notochord cell differentiation, resulting in the development of tailbud embryos with shorted tails. The expression of an actin gene that is normally expressed in mesenchyme cells was also suppressed. These results suggest that FGF signals are involved in differentiation of notochord cells and mesenchyme cells in Halocynthia embryos. Furthermore, the patterning of a neuron-specific tubulin gene expression was disturbed, suggesting that the formation of the nervous system was directly affected by disrupting FGF signals or indirectly affected due to the disruption of normal notochord formation.

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