scholarly journals Regulation of d-Aspartate Oxidase Gene Expression by Pyruvate Metabolism in the Yeast Cryptococcus humicola

2021 ◽  
Vol 9 (12) ◽  
pp. 2444
Author(s):  
Daiki Imanishi ◽  
Sota Zaitsu ◽  
Shouji Takahashi

d-Aspartate oxidase (DDO) is a peroxisomal flavoenzyme that catalyzes the oxidative deamination of acidic d-amino acids. In the yeast Cryptococcus humicola strain UJ1, the enzyme ChDDO is essential for d-Asp utilization and is expressed only in the presence of d-Asp. Pyruvate carboxylase (Pyc) catalyzes the conversion of pyruvate to oxaloacetate and is involved in the import and activation of certain peroxisomal flavoenzymes in yeasts. In this study, we analyzed the role of Pyc in the expression of ChDDO gene in C. humicola strain UJ1. PYC gene disruption (∆Chpyc1) in strain UJ1 resulted in growth retardation on glucose and NH4Cl medium. The growth was restored by supplying oxaloacetate from l-Asp or α-ketoglutarate by a transaminase. On the other hand, the supply of oxaloacetate from d-Asp by ChDDO was not able to prevent growth retardation because of a significant decrease in ChDDO gene expression at the transcriptional level. The addition of pyruvate significantly decreased ChDDO gene transcription in the ∆Chpyc1 strain but increased the same in the wild-type strain, even though the intracellular pyruvate content was similar in both strains. These results suggest that ChDDO gene expression might be regulated by pyruvate metabolism, as well as by the presence of d-Asp.

Open Biology ◽  
2017 ◽  
Vol 7 (7) ◽  
pp. 170087 ◽  
Author(s):  
Yi Ting Tsai ◽  
Valentina Salzman ◽  
Matías Cabruja ◽  
Gabriela Gago ◽  
Hugo Gramajo

One of the dominant features of the biology of Mycobacterium tuberculosis , and other mycobacteria, is the mycobacterial cell envelope with its exceptional complex composition. Mycolic acids are major and very specific components of the cell envelope and play a key role in its architecture and impermeability. Biosynthesis of mycolic acid (MA) precursors requires two types of fatty acid synthases, FAS I and FAS II, which should work in concert in order to keep lipid homeostasis tightly regulated. Both FAS systems are regulated at their transcriptional level by specific regulatory proteins. FasR regulates components of the FAS I system, whereas MabR and FadR regulate components of the FAS II system. In this article, by constructing a tight mabR conditional mutant in Mycobacterium smegmatis mc 2 155, we demonstrated that sub-physiological levels of MabR lead to a downregulation of the fasII genes, inferring that this protein is a transcriptional activator of the FAS II system. In vivo labelling experiments and lipidomic studies carried out in the wild-type and the mabR conditional mutant demonstrated that under conditions of reduced levels of MabR, there is a clear inhibition of biosynthesis of MAs, with a concomitant change in their relative composition, and of other MA-containing molecules. These studies also demonstrated a change in the phospholipid composition of the membrane of the mutant strain, with a significant increase of phosphatidylinositol. Gel shift assays carried out with MabR and P fasII as a probe in the presence of different chain-length acyl-CoAs strongly suggest that molecules longer than C 18 can be sensed by MabR to modulate its affinity for the operator sequences that it recognizes, and in that way switch on or off the MabR-dependent promoter. Finally, we demonstrated the direct role of MabR in the upregulation of the fasII operon genes after isoniazid treatment.


2020 ◽  
Author(s):  
Alexander C. West ◽  
Yasutaka Mizoro ◽  
Shona H. Wood ◽  
Louise M. Ince ◽  
Marianne Iversen ◽  
...  

AbstractAnadromous salmonids begin life adapted to the freshwater environments of their natal streams before a developmental transition, known as smoltification, transforms them into marine-adapted fish. In the wild, the extending photoperiods of spring stimulates smoltification, typified by radical reprogramming of the gill from an ion-absorbing organ to ion-excreting organ. Prior work has highlighted the role of specialized “mitochondrion-rich” cells in delivering this phenotype. However, transcriptomic studies identify thousands of smoltification-driven differentially regulated genes, indicating that smoltification causes a multifaceted, multicellular change; but direct evidence of this is lacking.Here, we use single-nuclei RNAseq to characterize the Atlantic salmon gill during smoltification and seawater transfer. We identify 20 distinct clusters of nuclei, including known, but also novel gill cell types. These data allow us to isolate cluster-specific, smoltification-induced changes in gene expression. We also show how cellular make-up of the gill changes through smoltification. As expected, we noted an increase in the proportion of seawater mitochondrion-rich cells, however, we also identify a reduction of several immune-related cells. Overall, our results provide unrivaled detail of the cellular complexity in the gill and suggest that smoltification triggers unexpected immune reprogramming directly preceding seawater entry.


2006 ◽  
Vol 37 (2) ◽  
pp. 341-352 ◽  
Author(s):  
Takanobu Sato ◽  
Kousuke Kitahara ◽  
Takao Susa ◽  
Takako Kato ◽  
Yukio Kato

Recently, we have reported that a Prophet of Pit-1 homeodomain factor, Prop-1, is a novel transcription factor for the porcine follicle-stimulating hormone β subunit (FSHβ) gene. This study subsequently aimed to examine the role of Prop-1 in the gene expression of two other porcine gonadotropin subunits, pituitary glycoprotein hormone α subunit (αGSU), and luteinizing hormone β subunit (LHβ). A series of deletion mutants of the porcine αGSU (up to −1059 bp) and LHβ (up to −1277 bp) promoters were constructed in the reporter vector, fused with the secreted alkaline phosphatase gene (pSEAP2-Basic). Transient transfection studies using GH3 cells were carried out to estimate the activation of the porcine αGSU and LHβ promoters by Prop-1, which was found to activate the αGSU promoter of −1059/+12 bp up to 11.7-fold but not the LHβ promoter. Electrophoretic mobility shift assay and DNase I footprinting analysis revealed that Prop-1 binds to six positions, −1038/−1026, −942/−928, −495/−479, −338/−326, −153/−146, and −131/−124 bp, that comprise the A/T cluster. Oligonucleotides of six Prop-1 binding sites were directly connected to the minimum promoter of αGSU, fused in the pSEAP2-Basic vector, followed by transfecting GH3 cells to determine the cis-acting activity. Finally, we concluded that at least five Prop-1 binding sites are the cis-acting elements for αGSU gene expression. The present results revealed a notable feature of the proximal region, where three Prop-1-binding sites are close to and/or overlap the pituitary glycoprotein hormone basal element, GATA-binding element, and junctional regulatory element. To our knowledge, this is the first demonstration of the role of Prop-1 in the regulation of αGSU gene expression. These results, taken together with our previous finding that Prop-1 is a transcription factor for FSHβ gene, confirm that Prop-1 modulates the synthesis of FSH at the transcriptional level. On the other hand, the defects of Prop-1 are known to cause dwarfism and combined pituitary hormone deficiency accompanying hypogonadism. Accordingly, the present observations provide a novel view to understand the hypogonadism caused by Prop-1 defects at the molecular level through the regulatory mechanism of αGSU and FSHβ gene expressions.


2014 ◽  
Vol 27 (1) ◽  
pp. 94-106 ◽  
Author(s):  
Emma L. Beckett ◽  
Zoe Yates ◽  
Martin Veysey ◽  
Konsta Duesing ◽  
Mark Lucock

A growing number of studies in recent years have highlighted the importance of molecular nutrition as a potential determinant of health and disease. In particular, the ability of micronutrients to regulate the final expression of gene products via modulation of transcription and translation is now being recognised. Modulation of microRNA (miRNA) by nutrients is one pathway by which nutrition may mediate gene expression. miRNA, a class of non-coding RNA, can directly regulate gene expression post-transcriptionally. In addition, miRNA are able to indirectly influence gene expression potential at the transcriptional level via modulation of the function of components of the epigenetic machinery (DNA methylation and histone modifications). These mechanisms interact to form a complex, bi-directional regulatory circuit modulating gene expression. Disease-specific miRNA profiles have been identified in multiple disease states, including those with known dietary risk factors. Therefore, the role that nutritional components, in particular, vitamins and minerals, play in the modulation of miRNA profiles, and consequently health and disease, is increasingly being investigated, and as such is a timely subject for review. The recently posited potential for viable exogenous miRNA to enter human blood circulation from food sources adds another interesting dimension to the potential for dietary miRNA to contribute to gene modulation.


2005 ◽  
Vol 73 (2) ◽  
pp. 748-760 ◽  
Author(s):  
Nuria Vergara-Irigaray ◽  
Alberto Chávarri-Martínez ◽  
Juan Rodríguez-Cuesta ◽  
Jeff F. Miller ◽  
Peggy A. Cotter ◽  
...  

ABSTRACT The BvgAS system of Bordetella pertussis was traditionally considered to mediate a transition between two phenotypic phases (Bvg+ and Bvg−) in response to environmental signals. We characterized a third state, the intermediate (Bvgi) phase, which can be induced by introducing a 1-bp substitution into bvgS (the bvgS-I1 mutation) or by growing B. pertussis under conditions intermediate between those leading to the Bvg+ and Bvg− phases. Like B. bronchiseptica, B. pertussis displays in its Bvgi phase a characteristic colony morphology and hemolytic activity and expresses a Bvgi-phase-specific polypeptide called BipA, whose synthesis is regulated by bvgAS at the transcriptional level. Based on our results, we hypothesize that the Bvgi phase of B. pertussis may be involved in facilitating transmission between hosts. Thus, a B. pertussis mutant carrying the bvgS-I1 mutation (GMT1i) persisted at wild-type levels only in the upper murine respiratory tract. Interestingly, a bipA deletion derivative of GMT1i displayed a reduced ability to colonize the nasal cavity of mice compared with GMT1i. However, in experimental mixed infections GMT1i expressing the Bvgi phase could establish an initial colonization in the nose and trachea of mice as efficiently as GMT1, but the wild-type strain outcompeted GMT1i at a later time point at all sites of the respiratory tract, suggesting that the Bvgi phase does not serve as a phenotypic phase specialized in colonization. Finally, even though B. pertussis expresses in vitro the Bvgi phase at the human nasal temperature, anti-BipA antibodies were undetectable in a large collection of sera from pertussis patients.


2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Hiroko Iijima ◽  
Atsuko Watanabe ◽  
Junko Takanobu ◽  
Masami Yokota Hirai ◽  
Takashi Osanai

The tricarboxylic acid (TCA) cycle and pyruvate metabolism of cyanobacteria are unique and important from the perspectives of biology and biotechnology research. Rre37, a response regulator induced by nitrogen depletion, activates gene expression related to sugar catabolism. Our previous microarray analysis has suggested that Rre37 controls the transcription of genes involved in sugar catabolism, pyruvate metabolism, and the TCA cycle. In this study, quantitative real-time PCR was used to measure the transcript levels of 12 TCA cycle genes and 13 pyruvate metabolism genes. The transcripts of 6 genes (acnB,icd,ppc,pyk1,me, andpta) increased after 4 h of nitrogen depletion in the wild-type GT strain but the induction was abolished byrre37overexpression. The repression of gene expression offumC, ddh, andackAcaused by nitrogen depletion was abolished byrre37overexpression. The expression ofmewas differently affected byrre37overexpression, compared to the other 24 genes. These results indicate that Rre37 differently controls the genes of the TCA cycle and pyruvate metabolism, implying the key reaction of the primary in this unicellular cyanobacterium.


MicroRNA ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Ling Lin ◽  
Kebin Hu

: MicroRNAs (miRNAs) are small non-coding RNAs (19~25 nucleotides) that regulate gene expression at a post-transcriptional level through repression of mRNA translation or mRNA decay. miR-147, which was initially discovered in mouse spleen and macrophages, has been shown to correlate with coronary atherogenesis and inflammatory bowel disease and modulate macrophage functions and inflammation through TLR-4. The altered miR-147 level has been shown in various human diseases, including infectious disease, cancer, cardiovascular disease, a neurodegenerative disorder, etc. This review will focus on the current understanding regarding the role of miR-147 in inflammation and diseases.


2019 ◽  
Vol 60 (9) ◽  
pp. 1897-1905 ◽  
Author(s):  
Akihiro Matsui ◽  
Kentaro Nakaminami ◽  
Motoaki Seki

Abstract Plant growth and productivity are greatly impacted by environmental stresses. Therefore, plants have evolved various sophisticated mechanisms for adaptation to nonoptimal environments. Recent studies using RNA metabolism-related mutants have revealed that RNA processing, RNA decay and RNA stability play an important role in regulating gene expression at a post-transcriptional level in response to abiotic stresses. Studies indicate that RNA metabolism is a unified network, and modification of stress adaptation-related transcripts at multiple steps of RNA metabolism is necessary to control abiotic stress-related gene expression. Recent studies have also demonstrated the important role of noncoding RNAs (ncRNAs) in regulating abiotic stress-related gene expression and revealed their involvement in various biological functions through their regulation of DNA methylation, DNA structural modifications, histone modifications and RNA–RNA interactions. ncRNAs regulate mRNA transcription and their synthesis is affected by mRNA processing and degradation. In the present review, recent findings pertaining to the role of the metabolic regulation of mRNAs and ncRNAs in abiotic stress adaptation are summarized and discussed.


Genes ◽  
2020 ◽  
Vol 11 (3) ◽  
pp. 319
Author(s):  
Saquib Waheed ◽  
Lihui Zeng

Flowering is an important biological process for plants that ensures reproductive success. The onset of flowering needs to be coordinated with an appropriate time of year, which requires tight control of gene expression acting in concert to form a regulatory network. MicroRNAs (miRNAs) are non-coding RNAs known as master modulators of gene expression at the post-transcriptional level. Many different miRNA families are involved in flowering-related processes such as the induction of floral competence, floral patterning, and the development of floral organs. This review highlights the diverse roles of miRNAs in controlling the flowering process and flower development, in combination with potential biotechnological applications for miRNAs implicated in flower regulation.


Microbiology ◽  
2009 ◽  
Vol 155 (1) ◽  
pp. 134-141 ◽  
Author(s):  
E. L. Denham ◽  
P. N. Ward ◽  
J. A. Leigh

The role of lipoprotein diacylglyceryl transferase (Lgt) and lipoprotein signal peptidase (Lsp) responsible for processing lipoproteins was investigated in Streptococcus uberis, a common cause of bovine mastitis. In the absence of Lgt, three lipoproteins [MtuA (SUB0473), Hap (SUB1625) and an extracellular solute-binding protein (SUB0365)] were detected in extracellular locations. All were shown by Edman degradation analysis to be cleaved on the carboxy side of the LXXC lipobox. Detection of MtuA, a lipoprotein shown previously to be essential for infectivity and virulence, was used as a surrogate lipoprotein marker to locate and assess processing of lipoproteins. The absence of Lgt did not prevent location of MtuA to the cell membrane, its location in the wild-type strain but, in contrast to the situation with wild-type, did result in a widespread location of this protein. In the absence of both Lgt and Lsp, MtuA was similarly released from the bacterial cell. In such strains, however, the cell-associated MtuA represented the full-length gene product, indicating that Lsp was able to cleave non-lipidated (lipo)proteins but was not responsible for their release from this bacterium.


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