scholarly journals Mutation of a palmitoyltransferase ZDHHC18-like gene is responsible for the minute wing mutation in the silkworm (Bombyx mori)

2017 ◽  
Author(s):  
Ye Yu ◽  
Xiaojing Liu ◽  
Xiao Ma ◽  
Zhongjie Zhang ◽  
Na Liu ◽  
...  
Keyword(s):  
Bombyx Mori ◽  
Positional Cloning ◽  
Molecular Mechanisms ◽  
Adult Stage ◽  
Significant Proportion ◽  
Gene Promoter ◽  
Wild Type ◽  
Evolutionarily Conserved ◽  
In The Wild ◽  
Hippo Signalling

AbstractPulpal- and adult-stage minute wing (mw) mutants of the silkworm Bombyx mori have much smaller wings than those of the wild type. Herein, we report the genetic and molecular mechanisms underling the formation of the minute wing. Fine mapping and positional cloning revealed that a palmitoyltransferase ZDHHC18-like gene (BmAPP）was responsible for the mw mutation. CRISPR/Cas9 screening of the BmAPP gene in wild-type embryos revealed that a significant proportion of adults had the mw mutation. In an mw mutant strain, u11, a 10-bp insertion in the promoter of a novel gene resulted in low-level translation of a protein belonging to the DHHC family. A PiggyBac-based transgenic analysis showed that the promoter induced the expression of aBmAPP gene promoter in the wild type but not the mw mutant. These findings indicate that functional deletion of this gene promoter accounts for the mw mutation in silkworm. The possibility that BmAPP gene is involved in Hippo signalling pathway, an evolutionarily conserved signaling pathway that controls organ size, is discussed.

scholarly journals Effect of Metallothionein-III on Mercury-Induced Chemokine Gene Expression

Toxics ◽  
2018 ◽  
Vol 6 (3) ◽  
pp. 48 ◽  
Author(s):  
Jin-Yong Lee ◽  
Maki Tokumoto ◽  
Gi-Wook Hwang ◽  
Min-Seok Kim ◽  
Tsutomu Takahashi ◽  
...  
Keyword(s):  
Gene Expression ◽  
Molecular Mechanisms ◽  
Mercury Vapor ◽  
Brain Diseases ◽  
Wild Type ◽  
Chemokine Gene ◽  
Mercury Compounds ◽  
In The Wild ◽  
The Brain ◽  
Chemokine Gene Expression

Mercury compounds are known to cause central nervous system disorders; however the detailed molecular mechanisms of their actions remain unclear. Methylmercury increases the expression of several chemokine genes, specifically in the brain, while metallothionein-III (MT-III) has a protective role against various brain diseases. In this study, we investigated the involvement of MT-III in chemokine gene expression changes in response to methylmercury and mercury vapor in the cerebrum and cerebellum of wild-type mice and MT-III null mice. No difference in mercury concentration was observed between the wild-type mice and MT-III null mice in any brain tissue examined. The expression of Ccl3 in the cerebrum and of Cxcl10 in the cerebellum was increased by methylmercury in the MT-III null but not the wild-type mice. The expression of Ccl7 in the cerebellum was increased by mercury vapor in the MT-III null mice but not the wild-type mice. However, the expression of Ccl12 and Cxcl12 was increased in the cerebrum by methylmercury only in the wild-type mice and the expression of Ccl3 in the cerebellum was increased by mercury vapor only in the wild-type mice. These results indicate that MT-III does not affect mercury accumulation in the brain, but that it affects the expression of some chemokine genes in response to mercury compounds.

Involvement of the Clock Gene period in the Circadian Rhythm of the Silkmoth Bombyx mori

2019 ◽  
Vol 34 (3) ◽  
pp. 283-292 ◽  
Author(s):  
Kento Ikeda ◽  
Takaaki Daimon ◽  
Hideki Sezutsu ◽  
Hiroko Udaka ◽  
Hideharu Numata
Keyword(s):  
Circadian Rhythm ◽  
Circadian Rhythms ◽  
Bombyx Mori ◽  
Negative Feedback ◽  
Masking Effect ◽  
Wild Type ◽  
Expression Levels ◽  
Knockout Strain ◽  
Behavioral Rhythms ◽  
In The Wild

In Lepidoptera, the roles of period ( per) and the negative feedback involving this gene in circadian rhythm are controversial. In the present study, we established a per knockout strain using TALEN in Bombyx mori, and compared eclosion and hatching rhythms between the per-knockout and wild-type strains to examine whether per is actually involved in these rhythms. The generated per knockout allele was considered null, because it encoded an extensively truncated form of PERIOD (198 aa due to a 64-bp deletion in exon 7, in contrast to 1113 aa in the wild-type protein). In this per knockout strain, circadian rhythms in eclosion and hatching were disrupted. Under LD cycles, however, a steep peak existed at 1 h after lights-on in both eclosion and hatching, and was considered to be produced by a masking effect—a direct response to light. In the per-knockout strain, temporal expression changes of per and timeless ( tim) were also lost. The expression levels of tim were continuously high, probably due to the loss of negative feedback by per and tim. In contrast, the expression levels of per were much lower in the per knockout strain than in the wild type at every time point. From these results, we concluded that per is indispensable for circadian rhythms, and we suggest that the negative feedback loop of the circadian rhythm involving per functions for the production of behavioral rhythms in B. mori.

scholarly journals Decreased Activity of the Ghrhr and Gh Promoters Causes Dominantly Inherited GH Deficiency in Humanized GH1 Mouse Models

Endocrinology ◽  
2019 ◽  
Vol 160 (11) ◽  
pp. 2673-2691
Author(s):  
Daisuke Ariyasu ◽  
Emika Kubo ◽  
Daisuke Higa ◽  
Shinsuke Shibata ◽  
Yutaka Takaoka ◽  
...  
Keyword(s):  
Molecular Mechanisms ◽  
Gh Deficiency ◽  
Gene Promoter ◽  
Dominant Negative ◽  
Hormone Deficiency ◽  
Dominant Negative Effect ◽  
Wild Type ◽  
New Paradigm ◽  
Gh Secretion

Abstract Isolated growth hormone deficiency type II (IGHD2) is mainly caused by heterozygous splice-site mutations in intron 3 of the GH1 gene. A dominant-negative effect of the mutant GH lacking exon 3 on wild-type GH secretion has been proposed; however, the molecular mechanisms involved are elusive. To uncover the molecular systems underlying GH deficiency in IGHD2, we established IGHD2 model mice, which carry both wild-type and mutant copies of the human GH1 gene, replacing each of the endogenous mouse Gh loci. Our IGHD2 model mice exhibited growth retardation along with intact cellular architecture and mildly activated endoplasmic reticulum stress in the pituitary gland, caused by decreased GH-releasing hormone receptor (Ghrhr) and Gh gene promoter activities. Decreased Ghrhr and Gh promoter activities were likely caused by reduced levels of nuclear CREB3L2, which was demonstrated to stimulate Ghrhr and Gh promoter activity. To our knowledge, this is the first in vivo study to reveal a novel molecular mechanism of GH deficiency in IGHD2, representing a new paradigm that differs from widely accepted models.

scholarly journals Deposition of Centromeric Histone H3 Variant CENP-A/Cse4 into Chromatin Is Facilitated by Its C-Terminal Sumoylation

Genetics ◽  
2020 ◽  
Vol 214 (4) ◽  
pp. 839-854 ◽  
Author(s):  
Kentaro Ohkuni ◽  
Evelyn Suva ◽  
Wei-Chun Au ◽  
Robert L. Walker ◽  
Reuben Levy-Myers ◽  
...  
Keyword(s):  
Molecular Mechanisms ◽  
Histone Chaperones ◽  
Wild Type ◽  
Link Type ◽  
C Terminus ◽  
Genome Wide ◽  
Evolutionarily Conserved ◽  
Histone H3 Variant ◽  
Assembly Factor ◽  
Active Investigation

Centromeric localization of CENP-A (Cse4 in Saccharomyces cerevisiae, CID in flies, CENP-A in humans) is essential for faithful chromosome segregation. Mislocalization of overexpressed CENP-A contributes to aneuploidy in yeast, flies, and humans, and is proposed to promote tumorigenesis in human cancers. Hence, defining molecular mechanisms that promote or prevent mislocalization of CENP-A is an area of active investigation. In budding yeast, evolutionarily conserved histone chaperones Scm3 and chromatin assembly factor-1 (CAF-1) promote localization of Cse4 to centromeric and noncentromeric regions, respectively. Ubiquitin ligases, such as Psh1 and Slx5, and histone chaperones (HIR complex) regulate proteolysis of overexpressed Cse4 and prevent its mislocalization to noncentromeric regions. In this study, we have identified sumoylation sites lysine (K) 215/216 in the C terminus of Cse4, and shown that sumoylation of Cse4 K215/216 facilitates its genome-wide deposition into chromatin when overexpressed. Our results showed reduced levels of sumoylation of mutant Cse4 K215/216R/A [K changed to arginine (R) or alanine (A)] and reduced interaction of mutant Cse4 K215/216R/A with Scm3 and CAF-1 when compared to wild-type Cse4. Consistent with these results, levels of Cse4 K215/216R/A in the chromatin fraction and localization to centromeric and noncentromeric regions were reduced. Furthermore, in contrast to GAL-CSE4, which exhibits Synthetic Dosage Lethality (SDL) in psh1∆, slx5∆, and hir2∆ strains, GAL-cse4 K215/216R does not exhibit SDL in these strains. Taken together, our results show that deposition of Cse4 into chromatin is facilitated by its C-terminal sumoylation.

scholarly journals NADPH Oxidase Is Crucial for the Cellular Redox Homeostasis in Fungal Pathogen Botrytis cinerea

2019 ◽  
Vol 32 (11) ◽  
pp. 1508-1516
Author(s):  
Hua Li ◽  
Shiping Tian ◽  
Guozheng Qin
Keyword(s):  
Nadph Oxidase ◽  
Botrytis Cinerea ◽  
Fungal Pathogen ◽  
Molecular Mechanisms ◽  
Redox Homeostasis ◽  
Signal Transduction Pathway ◽  
Regulatory Subunit ◽  
Wild Type ◽  
Mutant Proteins ◽  
In The Wild

During interactions, both plants and pathogens produce reactive oxygen species (ROS). Plants generate ROS for defense induction, while pathogens synthesize ROS for growth, sporulation, and virulence. NADPH oxidase (NOX) complex in the plasma membrane represents a main protein complex for ROS production in pathogens. Although NOX plays a crucial role in pathogenicity of pathogens, the underlying molecular mechanisms of NOX, especially the proteins regulated by NOX, remain largely unknown. Here, we applied an iodoacetyl tandem mass tag-based redox proteomic assay to investigate the protein redox dynamics in deletion mutant of bcnoxR, which encodes a regulatory subunit of NOX in the fungal pathogen Botrytis cinerea. In total, 214 unique peptidyl cysteine (Cys) thiols from 168 proteins were identified and quantified in both the wild type and ∆bcnoxR mutant. The Cys thiols in the ∆bcnoxR mutant were generally more oxidized than those in the wild type, suggesting that BcNoxR is essential for maintaining the equilibrium of the redox state in B. cinerea. Site-specific thiol oxidation analysis indicated that 142 peptides containing the oxidized thiols changed abundance significantly in the ∆bcnoxR mutant. Proteins containing these differential peptides are classified into various functional categories. Functional analysis revealed that one of these proteins, 6-phosphate dehydrogenase, played roles in oxidative stress response and pathogenesis of B. cinerea. These results provide insight into the potential target proteins and the ROS signal transduction pathway regulated by NOX.

scholarly journals The Type III Secretion Chaperone HpaB Controls the Translocation of Effector and Noneffector Proteins From Xanthomonas campestris pv. vesicatoria

2018 ◽  
Vol 31 (1) ◽  
pp. 61-74 ◽  
Author(s):  
Felix Scheibner ◽  
Nadine Hartmann ◽  
Jens Hausner ◽  
Christian Lorenz ◽  
Anne-Katrin Hoffmeister ◽  
...  
Keyword(s):  
Type Iii Secretion ◽  
Type Strain ◽  
Xanthomonas Campestris ◽  
Molecular Mechanisms ◽  
Wild Type Strain ◽  
Effector Proteins ◽  
Wild Type ◽  
Type Iii ◽  
In The Wild ◽  
Secretion Chaperone

Pathogenicity of the gram-negative bacterium Xanthomonas campestris pv. vesicatoria depends on a type III secretion (T3S) system, which translocates effector proteins into plant cells. Effector proteins contain N-terminal T3S and translocation signals and interact with the T3S chaperone HpaB, which presumably escorts effectors to the secretion apparatus. The molecular mechanisms underlying the recognition of effectors by the T3S system are not yet understood. In the present study, we analyzed T3S and translocation signals in the type III effectors XopE2 and XopJ from X. campestris pv. vesicatoria. Both effectors contain minimal translocation signals, which are only recognized in the absence of HpaB. Additional N-terminal signals promote translocation of XopE2 and XopJ in the wild-type strain. The results of translocation and interaction studies revealed that the interaction of XopE2 and XopJ with HpaB and a predicted cytoplasmic substrate docking site of the T3S system is not sufficient for translocation. In agreement with this finding, we show that the presence of an artificial HpaB-binding site does not promote translocation of the noneffector XopA in the wild-type strain. Our data, therefore, suggest that the T3S chaperone HpaB not only acts as an escort protein but also controls the recognition of translocation signals.

scholarly journals Transgenic Ectopic Overexpression of Broad Complex (BrC-Z2) in the Silk Gland Inhibits the Expression of Silk Fibroin Genes of Bombyx mori

Insects ◽  
2020 ◽  
Vol 11 (6) ◽  
pp. 374
Author(s):  
Jiangshan Cong ◽  
Cuicui Tao ◽  
Xuan Zhang ◽  
Hui Zhang ◽  
Tingcai Cheng ◽  
...  
Keyword(s):  
Bombyx Mori ◽  
Developmental Stages ◽  
Expression Patterns ◽  
Silk Gland ◽  
Silk Protein ◽  
Regulation Mechanism ◽  
Wild Type ◽  
Transgenic Lines ◽  
In The Wild ◽  
Broad Complex

Bombyx mori silk protein genes are strictly turned on and off in different developmental stages under the hormone periodically change. The broad complex (BrC) is a transcription factor mediating 20-hydroxyecdysone action, which plays important roles during metamorphosis. Here, we observed that two isoforms of BmBrC (BmBrC-Z2 and BmBrC-Z4) exhibited contrasting expression patterns with fibroin genes (FibH, FibL and P25) in the posterior silk gland (PSG), suggesting that BmBrC may negatively regulate fibroin genes. Transgenic lines were constructed to ectopically overexpress BmBrC-Z2 in the PSG. The silk protein genes in the transgenic line were decreased to almost half of that in the wild type. The silk yield was decreased significantly. In addition, the expression levels of regulatory factors (BmKr-h1 and BmDimm) response to juvenile hormone (JH) signal were inhibited significantly. Then exogenous JH in the BmBrC-Z2 overexpressed lines can inhibit the expression of BmBrC-Z2 and activate the expression of silk protein genes and restore the silk yield to the level of the wild type. These results indicated that BmBrC may inhibit fibroin genes by repressing the JH signal pathway, which would assist in deciphering the comprehensive regulation mechanism of silk protein genes.

scholarly journals Neurofilament deficiency in quail caused by nonsense mutation in neurofilament-L gene.

1993 ◽  
Vol 121 (2) ◽  
pp. 387-395 ◽  
Author(s):  
O Ohara ◽  
Y Gahara ◽  
T Miyake ◽  
H Teraoka ◽  
T Kitamura
Keyword(s):  
Gene Expression ◽  
Amino Acid ◽  
Japanese Quail ◽  
Nonsense Mutation ◽  
Trace Amount ◽  
Molecular Mechanisms ◽  
Deficient Mutant ◽  
Wild Type ◽  
In The Wild ◽  
Genetic Events

The existence of a neurofilament-deficient mutant of Japanese quail was recently documented (Yamasaki, H., C. Itakura, and M. Mizutani. 1991. Acta Neuropathol. 82:427-434), but the genetic events leading to the neurofilament deficiency have yet to be determined. Our molecular biological analyses revealed that the expression of neurofilament-L (NF-L) gene was specifically repressed in neurons of this mutant. To search for mutation(s) responsible for the shutdown of this gene expression, we cloned and sequenced the NF-L genes in the wild-type and mutant quails. It is eventually found that the NF-L gene in the mutant includes a nonsense mutation at the deduced amino acid residue 114, indicating that the mutant is incapable of producing even a trace amount of polymerization-competent NF-L protein at any situation. The identification of this nonsense mutation provides us with a solid basis on which molecular mechanisms underlying the alteration in the neuronal cytoskeletal architecture in the mutant should be interpreted.

scholarly journals Citrus PH4–Noemi regulatory complex is involved in proanthocyanidin biosynthesis via a positive feedback loop

2019 ◽  
Vol 71 (4) ◽  
pp. 1306-1321 ◽  
Author(s):  
Yin Zhang ◽  
Junli Ye ◽  
Chaoyang Liu ◽  
Qiang Xu ◽  
Lichang Long ◽  
...  
Keyword(s):  
Fruit Quality ◽  
Positive Feedback ◽  
Feedback Loop ◽  
Molecular Mechanisms ◽  
Citrus Fruit ◽  
Wild Type ◽  
Biosynthetic Genes ◽  
Positive Feedback Loop ◽  
Regulatory Complex ◽  
In The Wild

Abstract Proanthocyanidins (PAs; or condensed tannins) are a major class of flavonoids that contribute to citrus fruit quality. However, the molecular mechanism responsible for PA biosynthesis and accumulation in citrus remains unclear. Here, we identify a PH4–Noemi regulatory complex that regulates proanthocyanidin biosynthesis in citrus. Overexpression of PH4 or Noemi in citrus calli activated the expression of PA biosynthetic genes and significantly increased the PA content. Interestingly, Noemi was also shown to be up-regulated in CsPH4-overexpressing lines compared with wild-type calli. Simultaneously, CsPH4 partially complemented the PA-deficient phenotype of the Arabidopsis tt2 mutant and promoted PA accumulation in the wild-type. Further analysis revealed that CsPH4 interacted with Noemi, and together these proteins synergistically activated the expression of PA biosynthetic genes by directly binding to the MYB-recognizing elements (MRE) of the promoters of these genes. Moreover, CsPH4 could directly bind to the promoter of Noemi and up-regulate the expression of this gene. These findings explain how the CsPH4–Noemi regulatory complex contributes to the activation of PA biosynthetic genes via a positive feedback loop and provide new insights into the molecular mechanisms underlying PA biosynthesis, which can be effectively employed for metabolic engineering to improve citrus fruit quality.

scholarly journals Methionine sulphoxide reductases protect iron–sulphur clusters from oxidative inactivation in yeast

Microbiology ◽  
2009 ◽  
Vol 155 (2) ◽  
pp. 612-623 ◽  
Author(s):  
Theodora C. Sideri ◽  
Sylvia A. Willetts ◽  
Simon V. Avery
Keyword(s):  
Molecular Mechanisms ◽  
Copper Resistance ◽  
Wild Type ◽  
Resistance Phenotype ◽  
Oxidative Inactivation ◽  
In The Wild ◽  
Methionine Residues ◽  
Cu Resistance ◽  
Fe Homeostasis ◽  
Yeast Mutants

Methionine residues and iron–sulphur (FeS) clusters are primary targets of reactive oxygen species in the proteins of micro-organisms. Here, we show that methionine redox modifications help to preserve essential FeS cluster activities in yeast. Mutants defective for the highly conserved methionine sulphoxide reductases (MSRs; which re-reduce oxidized methionines) are sensitive to many pro-oxidants, but here exhibited an unexpected copper resistance. This phenotype was mimicked by methionine sulphoxide supplementation. Microarray analyses highlighted several Cu and Fe homeostasis genes that were upregulated in the mxrΔ double mutant, which lacks both of the yeast MSRs. Of the upregulated genes, the Cu-binding Fe transporter Fet3p proved to be required for the Cu-resistance phenotype. FET3 is known to be regulated by the Aft1 transcription factor, which responds to low mitochondrial FeS-cluster status. Here, constitutive Aft1p expression in the wild-type reproduced the Cu-resistance phenotype, and FeS-cluster functions were found to be defective in the mxrΔ mutant. Genetic perturbation of FeS activity also mimicked FET3-dependent Cu resistance. 55Fe-labelling studies showed that FeS clusters are turned over more rapidly in the mxrΔ mutant than the wild-type, consistent with elevated oxidative targeting of the clusters in MSR-deficient cells. The potential underlying molecular mechanisms of this targeting are discussed. Moreover, the results indicate an important new role for cellular MSR enzymes in helping to protect the essential function of FeS clusters in aerobic settings.

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