scholarly journals Proprotein Convertase Furina Is Required for Heart Development in Zebrafish

2021 ◽  
Author(s):  
Qinchao Zhou ◽  
Lei Lei ◽  
Hefei Zhang ◽  
Shih-Ching Chiu ◽  
Lu Gao ◽  
...  

Cardiac looping and trabeculation are key processes during cardiac chamber maturation. However, the underlying mechanisms remain incompletely understood. Here, we report the isolation, cloning, and characterization of the proprotein convertase furina from the cardiovascular mutant loft in zebrafish. loft is an ethylnitrosourea-induced mutant and has evident defects in the cardiac outflow tract, heart looping and trabeculation, the craniofacial region, and pharyngeal arch arteries. Positional cloning revealed that furina mRNA was barely detectable in loft mutants, and loft failed to complement the TALEN-induced furina mutant pku338, confirming that furina is responsible for the loft mutant phenotypes. Mechanistic studies demonstrated that Notch reporter Tg(tp1:mCherry) signals were largely eliminated in mutant hearts, while over-expression of NICD partially rescued the mutant phenotypes, probably due to the lack of Furina-mediated cleavage processing of Notch1b proteins, the only Notch receptor expressed in the heart. Together, our data suggest a potential post-translational modification of Notch1b proteins via the proprotein convertase Furina in the heart and unveil the function of the Furina-Notch1b axis in cardiac looping and trabeculation in zebrafish and possibly in other organisms.

2020 ◽  
Vol 17 (5) ◽  
pp. 379-391
Author(s):  
Farzaneh Afzali ◽  
Parisa Ghahremanifard ◽  
Mohammad Mehdi Ranjbar ◽  
Mahdieh Salimi

Background: The tolerogenic homeostasis in Breast Cancer (BC) can be surpassed by rationally designed immune-encouraging constructs against tumor-specific antigens through immunoinformatics approach. Objective: Availability of high throughput data providing the underlying concept of diseases and awarded computational simulations, lead to screening the potential medications and strategies in less time and cost. Despite the extensive effects of Placenta Specific 1 (PLAC1) in BC progression, immune tolerance, invasion, cell cycle regulation, and being a tumor-specific antigen the fundamental mechanisms and regulatory factors were not fully explored. It is also worth to design an immune response inducing construct to surpass the hurdles of traditional anti-cancer treatments. Methods and Result: The study was initiated by predicting and modelling the PLAC1 secondary and tertiary structures and then engineering the fusion pattern of PLAC1 derived immunodominant predicted CD8+ and B-cell epitopes to form a multi-epitope immunogenic construct. The construct was analyzed considering the physiochemical characterization, safety, antigenicity, post-translational modification, solubility, and intrinsically disordered regions. After modelling its tertiary structure, proteinprotein docking simulation was carried out to ensure the attachment of construct with Toll-Like Receptor 4 (TLR4) as an immune receptor. To guarantee the highest expression of the designed construct in E. coli k12 as an expressional host, the codon optimization and in-silico cloning were performed. The PLAC1 related miRNAs in BC were excavated and validated through TCGA BC miRNA-sequencing and databases; the common pathways then were introduced as other probable mechanisms of PLAC1 activity. Conclusion: Regarding the obtained in-silico results, the designed anti-PLAC1 multi-epitope construct can probably trigger humoral and cellular immune responses and inflammatory cascades, therefore may have the potential of halting BC progression and invasion engaging predicted pathways.


Viruses ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1393
Author(s):  
Thanyaporn Dechtawewat ◽  
Sittiruk Roytrakul ◽  
Yodying Yingchutrakul ◽  
Sawanya Charoenlappanit ◽  
Bunpote Siridechadilok ◽  
...  

Dengue virus (DENV) infection causes a spectrum of dengue diseases that have unclear underlying mechanisms. Nonstructural protein 1 (NS1) is a multifunctional protein of DENV that is involved in DENV infection and dengue pathogenesis. This study investigated the potential post-translational modification of DENV NS1 by phosphorylation following DENV infection. Using liquid chromatography-tandem mass spectrometry (LC-MS/MS), 24 potential phosphorylation sites were identified in both cell-associated and extracellular NS1 proteins from three different cell lines infected with DENV. Cell-free kinase assays also demonstrated kinase activity in purified preparations of DENV NS1 proteins. Further studies were conducted to determine the roles of specific phosphorylation sites on NS1 proteins by site-directed mutagenesis with alanine substitution. The T27A and Y32A mutations had a deleterious effect on DENV infectivity. The T29A, T230A, and S233A mutations significantly decreased the production of infectious DENV but did not affect relative levels of intracellular DENV NS1 expression or NS1 secretion. Only the T230A mutation led to a significant reduction of detectable DENV NS1 dimers in virus-infected cells; however, none of the mutations interfered with DENV NS1 oligomeric formation. These findings highlight the importance of DENV NS1 phosphorylation that may pave the way for future target-specific antiviral drug design.


Author(s):  
Evan S. Bardot ◽  
Bharati Jadhav ◽  
Nadeera Wickramasinghe ◽  
Amélie Rezza ◽  
Michael Rendl ◽  
...  

AbstractDuring development multiple progenitor populations contribute to the formation of the four-chambered heart and its diverse lineages. However, the underlying mechanisms that result in the specification of these progenitor populations are not yet fully understood. We have previously identified a population of cells that gives rise selectively to the heart ventricles but not the atria. Here, we have used this knowledge to transcriptionally profile subsets of cardiac mesoderm from the mouse embryo and have identified an enrichment for Notch signaling components in ventricular progenitors. Using directed differentiation of human pluripotent stem cells, we next investigated the role of Notch in cardiac mesoderm specification in a temporally controlled manner. We show that transient Notch induction in mesoderm increases cardiomyocyte differentiation efficiency, while maintaining cardiomyocytes in an immature state. Finally, our data suggest that Notch interacts with WNT to enhance commitment to the cardiac lineage. Overall, our findings support the notion that key signaling events during early heart development are critical for proper lineage specification and provide evidence for early roles of Notch and WNT during mouse and human heart development.Summary statementEarly fate decisions are dictated by the embryonic signaling environment. We show that Notch signaling is active during early mouse development and that activating Notch in human cardiac mesoderm enhances cardiomyocyte differentiation efficiency.


Development ◽  
1999 ◽  
Vol 126 (6) ◽  
pp. 1269-1280 ◽  
Author(s):  
M. Tanaka ◽  
Z. Chen ◽  
S. Bartunkova ◽  
N. Yamasaki ◽  
S. Izumo

Csx/Nkx2.5 is a vertebrate homeobox gene with a sequence homology to the Drosophila tinman, which is required for the dorsal mesoderm specification. Recently, heterozygous mutations of this gene were found to cause human congenital heart disease (Schott, J.-J., Benson, D. W., Basson, C. T., Pease, W., Silberbach, G. M., Moak, J. P., Maron, B. J., Seidman, C. E. and Seidman, J. G. (1998) Science 281, 108–111). To investigate the functions of Csx/Nkx2.5 in cardiac and extracardiac development in the vertebrate, we have generated and analyzed mutant mice completely null for Csx/Nkx2.5. Homozygous null embryos showed arrest of cardiac development after looping and poor development of blood vessels. Moreover, there were severe defects in vascular formation and hematopoiesis in the mutant yolk sac. Interestingly, TUNEL staining and PCNA staining showed neither enhanced apoptosis nor reduced cell proliferation in the mutant myocardium. In situ hybridization studies demonstrated that, among 20 candidate genes examined, expression of ANF, BNP, MLC2V, N-myc, MEF2C, HAND1 and Msx2 was disturbed in the mutant heart. Moreover, in the heart of adult chimeric mice generated from Csx/Nkx2.5 null ES cells, there were almost no ES cell-derived cardiac myocytes, while there were substantial contributions of Csx /Nkx2.5-deficient cells in other organs. Whole-mount β-gal staining of chimeric embryos showed that more than 20% contribution of Csx/Nkx2. 5-deficient cells in the heart arrested cardiac development. These results indicate that (1) the complete null mutation of Csx/Nkx2.5 did not abolish initial heart looping, (2) there was no enhanced apoptosis or defective cell cycle entry in Csx/Nkx2.5 null cardiac myocytes, (3) Csx/Nkx2.5 regulates expression of several essential transcription factors in the developing heart, (4) Csx/Nkx2.5 is required for later differentiation of cardiac myocytes, (5) Csx/Nkx2. 5 null cells exert dominant interfering effects on cardiac development, and (6) there were severe defects in yolk sac angiogenesis and hematopoiesis in the Csx/Nkx2.5 null embryos.


2020 ◽  
Vol 71 (5) ◽  
pp. 1681-1693 ◽  
Author(s):  
Michaela S Matthes ◽  
Janlo M Robil ◽  
Paula McSteen

Abstract Deficiency of the essential nutrient boron (B) in the soil is one of the most widespread micronutrient deficiencies worldwide, leading to developmental defects in root and shoot tissues of plants, and severe yield reductions in many crops. Despite this agricultural importance, the underlying mechanisms of how B shapes plant developmental and morphological processes are still not unequivocally understood in detail. This review evaluates experimental approaches that address our current understanding of how B influences plant morphological processes by focusing on developmental defects observed under B deficiency. We assess what is known about mechanisms that control B homeostasis and specifically highlight: (i) limitations in the methodology that is used to induce B deficiency; (ii) differences between mutant phenotypes and normal plants grown under B deficiency; and (iii) recent research on analyzing interactions between B and phytohormones. Our analysis highlights the need for standardized methodology to evaluate the roles of B in the cell wall versus other parts of the cell.


2007 ◽  
Vol 05 (06) ◽  
pp. 1193-1213 ◽  
Author(s):  
CHI-REN SHYU ◽  
JATURON HARNSOMBURANA ◽  
JASON GREEN ◽  
ADRIAN S. BARB ◽  
TONI KAZIC ◽  
...  

There are thousands of maize mutants, which are invaluable resources for plant research. Geneticists use them to study underlying mechanisms of biochemistry, cell biology, cell development, and cell physiology. To streamline the understanding of such complex processes, researchers need the most current versions of genetic and physical maps, tools with the ability to recognize novel phenotypes or classify known phenotypes, and an intimate knowledge of the biochemical processes generating physiological and phenotypic effects. They must also know how all of these factors change and differ among species, diverse alleles, germplasms, and environmental conditions. While there are robust databases, such as MaizeGDB, for some of these types of raw data, other crucial components are missing. Moreover, the management of visually observed mutant phenotypes is still in its infant stage, let alone the complex query methods that can draw upon high-level and aggregated information to answer the questions of geneticists. In this paper, we address the scientific challenge and propose to develop a robust framework for managing the knowledge of visually observed phenotypes, mining the correlation of visual characteristics with genetic maps, and discovering the knowledge relating to cross-species conservation of visual and genetic patterns. The ultimate goal of this research is to allow a geneticist to submit phenotypic and genomic information on a mutant to a knowledge base and ask, "What genes or environmental factors cause this visually observed phenotype?".


Genetics ◽  
1999 ◽  
Vol 152 (2) ◽  
pp. 577-593 ◽  
Author(s):  
Robert A Rollins ◽  
Patrick Morcillo ◽  
Dale Dorsett

Abstract How enhancers are able to activate promoters located several kilobases away is unknown. Activation by the wing margin enhancer in the cut gene, located 85 kb from the promoter, requires several genes that participate in the Notch receptor pathway in the wing margin, including scalloped, vestigial, mastermind, Chip, and the Nipped locus. Here we show that Nipped mutations disrupt one or more of four essential complementation groups: l(2)41Ae, l(2)41Af, Nipped-A, and Nipped-B. Heterozygous Nipped mutations modify Notch mutant phenotypes in the wing margin and other tissues, and magnify the effects that mutations in the cis regulatory region of cut have on cut expression. Nipped-A and l(2)41Af mutations further diminish activation by a wing margin enhancer partly impaired by a small deletion. In contrast, Nipped-B mutations do not diminish activation by the impaired enhancer, but increase the inhibitory effect of a gypsy transposon insertion between the enhancer and promoter. Nipped-B mutations also magnify the effect of a gypsy insertion in the Ultrabithorax gene. Gypsy binds the Suppressor of Hairy-wing insulator protein [Su(Hw)] that blocks enhancer-promoter communication. Increased insulation by Su(Hw) in Nipped-B mutants suggests that Nipped-B products structurally facilitate enhancer-promoter communication. Compatible with this idea, Nipped-B protein is homologous to a family of chromosomal adherins with broad roles in sister chromatid cohesion, chromosome condensation, and DNA repair.


2018 ◽  
Author(s):  
Michal Pawlak ◽  
Katarzyna Z. Kedzierska ◽  
Maciej Migdal ◽  
Karim Abu Nahia ◽  
Jordan A. Ramilowski ◽  
...  

ABSTRACTThe development of an organ involves dynamic regulation of gene transcription and complex multipathway interactions. To better understand transcriptional regulatory mechanism driving heart development and the consequences of its disruption, we isolated cardiomyocytes (CMs) from wild-type zebrafish embryos at 24, 48 and 72 hours post fertilization corresponding to heart looping, chamber formation and heart maturation, and from mutant lines carrying loss-of-function mutations in gata5, tbx5a and hand2, transcription factors (TFs) required for proper heart development. The integration of CM transcriptomics (RNA-seq) and genome-wide chromatin accessibility maps (ATAC-seq) unravelled dynamic regulatory networks driving crucial events of heart development. These networks contained key cardiac TFs including Gata5/6, Nkx2.5, Tbx5/20, and Hand2, and are associated with open chromatin regions enriched for DNA sequence motifs belonging to the family of the corresponding TFs. These networks were disrupted in cardiac TF mutants, indicating their importance in proper heart development. The most prominent gene expression changes, which correlated with chromatin accessibility modifications within their proximal promoter regions, occurred between heart looping and chamber formation, and were associated with metabolic and hematopoietic/cardiac switch during CM maturation. Furthermore, loss of function of cardiac TFs Gata5, Tbx5a, and Hand2 affected the cardiac regulatory networks and caused global changes in chromatin accessibility profile. Among regions with differential chromatin accessibility in mutants were highly conserved non-coding elements which represent putative cis regulatory elements with potential role in heart development and disease. Altogether, our results revealed the dynamic regulatory landscape at key stages of heart development and identified molecular drivers of heart morphogenesis.


2020 ◽  
Author(s):  
Federico Tessadori ◽  
Fabian Kruse ◽  
Susanne C. van den Brink ◽  
Malou van den Boogaard ◽  
Vincent M. Christoffels ◽  
...  

AbstractOrgan laterality refers to the Left-Right (LR) asymmetry in disposition and conformation of internal organs, established in the developing embryo. The heart is the first organ to display visible LR asymmetries as it is positioned to the left side of the midline and undergoes rightward looping morphogenesis. Cardiac looping morphogenesis is tightly controlled by a combination of heart-intrinsic and -extrinsic mechanisms. As the mechanisms that drive cardiac looping are not well understood, we performed a forward genetic screen for zebrafish mutants with defective heart looping. We describe a new loss-of-function allele for tbx5a, which displays normal leftward positioning but defective rightward looping morphogenesis. By using live two-photon confocal imaging to map cardiomyocyte behavior during cardiac looping at a single-cell level we establish that during looping, ventricular and atrial cardiomyocytes rearrange in opposite directions towards the outer curvatures of the chambers. As a consequence, the cardiac chambers twist around the atrioventricular canal resulting in torsion of the heart tube, which is compromised in tbx5a mutants. Manipulations of cardiac looping by chemical treatment and ex vivo culture establishes that the twisting of the heart tube depends on intrinsic mechanisms and is independent from tissue growth by cell addition. Furthermore, the cardiac looping defect in tbx5a mutants is rescued in tbx5a/tbx2b double mutants, indicating that it requires proper tissue patterning. Together, our results establish that cardiac looping in zebrafish involves twisting of the chambers around the AV canal, which requires correct tissue patterning by Tbx5a.


2020 ◽  
Author(s):  
Ru Chang Ren ◽  
Xu Wei Yan ◽  
Ya Jie Zhao ◽  
Yi Ming Wei ◽  
Xiaoduo Lu ◽  
...  

Abstract Background Pentatricopeptide repeat (PPR) proteins is a large protein family, which participate in RNA processing in organelles and plant growth. Previous reports have generally considered E-subgroup PPR proteins as an editing factors for RNA editing. However, the underlying mechanisms and effects of E-subgroup PPR proteins remain to be investigated.Results In this study, we recognized and identified a new maize kernel mutant with arrested embryo and endosperm development, defective kernel 55 (dek55). Genetic and molecular evidences suggest that the defective kernels resulted from a mononucleotide alteration (C to T) at + 449 in the open reading frame (ORF) of Zm00001d014471 (hereafter referred to as DEK55). DEK55 encodes an E-subgroup PPR protein within mitochondria. Molecular analyses suggest that DEK55 plays crucial roles in RNA editing at multiple sites of ribosomal protein S13, ATP synthase subunit1, NADH dehydrogenase-6 (nad6), and nad9 transcripts as well as in splicing of nad1 and nad4. The mutation of DEK55 lead to the dysfunction of mitochondrial complex I.Conclusions Our results demonstrate that the DEK55 mutation is responsible for the dek55 mutant phenotypes, as it affects mitochondrial function that is essential for maize kernel development. This study also provides novel insight into the molecular function of E-subgroup PPR proteins in plant organellar RNA metabolism.


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