scholarly journals Complex N-Glycans Are Important for Normal Fruit Ripening and Seed Development in Tomato

2021 ◽  
Vol 12 ◽  
Author(s):  
Heidi Kaulfürst-Soboll ◽  
Melanie Mertens-Beer ◽  
Randolf Brehler ◽  
Markus Albert ◽  
Antje von Schaewen

Complex N-glycan modification of secretory glycoproteins in plants is still not well understood. Essential in animals, where a lack of complex N-glycans is embryo-lethal, their presence in plants seemed less relevant for a long time mostly because Arabidopsis thaliana cgl1 mutants lacking N-acetyl-glucosaminyltransferase I (GNTI, the enzyme initiating complex N-glycan maturation in the Golgi apparatus) are viable and showed only minor impairments regarding stress tolerance or development. A different picture emerged when a rice (Oryza sativa) gntI T-DNA mutant was found to be unable to reach the reproductive stage. Here, we report on tomato (Solanum lycopersicum) lines that showed severe impairments upon two RNA interference (RNAi) approaches. Originally created to shed light on the role of core α1,3-fucose and β1,2-xylose residues in food allergy, plants with strongly reduced GNTI activity developed necrotic fruit-attached stalks and early fruit drop combined with patchy incomplete ripening. Correspondingly, semiquantitative RT-PCR of the abscission zone (az) revealed an increase of abscission markers. Also, GNTI-RNA interference (RNAi) plants were more susceptible to sporadic infection. To obtain vital tomatoes with comparable low allergenic potential, Golgi α-mannosidase II (MANII) was chosen as the second target. The resulting phenotypes were oppositional: MANII-reduced plants carried normal-looking fruits that remained attached for extended time without signs of necrosis. Fruits contained no or only few, but enlarged, seeds. Furthermore, leaves developed rolled-up rims simultaneously during the reproductive stage. Trials to cross MANII-reduced plants failed, while GNTI-reduced plants could be (back-)crossed, retaining their characteristic phenotype. This phenotype could not be overcome by ethephon or indole-3-acetic acid (IAA) application, but the latter was able to mimic patchy fruit ripening in wild-type. Phytohormones measured in leaves and 1-aminocyclopropane-1-carboxylic acid (ACC) contents in fruits showed no significant differences. Together, the findings hint at altered liberation/perception of protein-bound N-glycans, known to trigger auxin-like effects. Concomitantly, semiquantitative RT-PCR analysis revealed differences in auxin-responsive genes, indicating the importance of complex N-glycan modification for hormone signaling/crosstalk. Another possible role of altered glycoprotein life span seems subordinate, as concluded from transient expression of Arabidopsis KORRIGAN KOR1-GFP fusion proteins in RNAi plants of Nicotiana benthamiana. In summary, our analyses stress the importance of complex N-glycan maturation for normal plant responses, especially in fruit-bearing crops like tomato.

Author(s):  
Marco Zschoche ◽  
Sergej Skosyrski ◽  
Neele Babst ◽  
Mahdy Ranjbar ◽  
Felix Rommel ◽  
...  

Abstract Background The role of CD133 und ABCB5 is discussed in treatment resistance in several types of cancer. The objective of this study was to evaluate whether CD133+/ABCB5+ colocalization differs in untreated, in beam radiation treated, and in chemotherapy treated retinoblastoma specimens. Additionally, CD133, ABCB5, sphingosine kinase 1, and sphingosine kinase 2 gene expression was analyzed in WERI-RB1 (WERI RB1) and etoposide-resistant WERI RB1 subclones (WERI ETOR). Methods Active human untreated retinoblastoma specimens (n = 12), active human retinoblastoma specimens pretreated with beam radiation before enucleation (n = 8), and active human retinoblastoma specimens pretreated with chemotherapy before enucleation (n = 7) were investigated for localization and expression of CD133 and ABCB5 by immunohistochemistry. Only specimens with IIRC D, but not E, were included in this study. Furthermore, WERI RB1 and WERI ETOR cell lines were analyzed for CD133, ABCB5, sphingosine kinase 1, and sphingosine kinase 2 by the real-time polymerase chain reaction (RT-PCR). Results Immunohistochemical analysis revealed the same amount of CD133+/ABCB5+ colocalization islets in untreated and treated human retinoblastoma specimens. Quantitative RT-PCR analysis showed a statistically significant upregulation of CD133 in WERI ETOR (p = 0.002). No ABCB5 expression was detected in WERI RB1 and WERI ETOR. On the other hand, SPHK1 (p = 0.0027) and SPHK2 (p = 0.017) showed significant downregulation in WERI ETOR compared to WERI RB1. Conclusions CD133+/ABCB5+ co-localization islets were noted in untreated and treated human retinoblastoma specimens. Therefore, we assume that CD133+/ABCB5+ islets might play a role in retinoblastoma genesis, but not in retinoblastoma treatment resistance.


Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 2213-2213
Author(s):  
J. Pulikkan ◽  
A. Peer Zada ◽  
M. Geletu ◽  
V. Dengler ◽  
Daniel G. Tenen ◽  
...  

Abstract CCAAT enhancer binding protein alpha (C/EBPα) is a myeloid specific transcription factor that coordinates cellular differentiation and cell cycle arrest. Loss of C/EBPα expression or function in leukemic blasts contributes to a block in myeloid cell differentiation. C/EBPα is mutated in around 9% of acute myeloid leukemia (AML). The mutations reported in C/EBPα are frame shift mutations and point mutations at basic region Leucine zipper. The mutant form of C/EBPα ie C/EBPα-p30 exhibits dominant negative function over the wild type protein. The role of peptidyl-prolyl cis/trans isomerase, Pin1 in tumorogenesis and its overexpression in many cancers led us to investigate its role in acute myeloid leukemia with C/EBPα mutation. Here we show that Pin1 is upregulated in patients with acute myeloid leukemia by affymetrix analysis. By quantitative Real-Time RT-PCR analysis, we show C/EBPα-p30 could induce Pin1 transcription, while the wild type C/EBPα downregulates Pin1 expression. Luciferase promoter assay for the Pin1 promoter shows that wild type C/EBPα is able to block Pin1 promoter activity. Mean while, C/EBPα-p30 couldn’t block Pin1 promotor activity. By silencing Pin1 by RNA Interference as well as with inhibitor against Pin1 (PiB) we could show myeloid differentiation in human CD34+ cord blood cells as well as in Kasumi-6 cells as assessed by FACS analysis with granulocytic markers. We investigated the mechanism underlying the dominant negative action of C/EBPα-p30 over the wild type protein. We report that Pin1 increases the transcriptional activity of the oncogene c-jun. We also show that c-jun blocks the DNA binding and transactivation of C/EBPα protein as assessed by gel shift assay and promoter assay respectively. We have previously shown that c-jun expression is high in AML patients with C/EBPα mutation and c-jun could block C/EBPα function by protein-protein interaction. Quantitative Real-Time RT-PCR analysis shows that inhibition of Pin1 by the inhibitor PiB downregulates c-jun mRNA expression. In conclusion, inhibition of Pin1 leads to granulocytic differentiation. Our results show Pin1 as a novel target in treating AML patients with C/EBPα mutation.


2019 ◽  
Vol 17 (1) ◽  
pp. e1004 ◽  
Author(s):  
Darko Jevremović ◽  
Aleksandar Leposavić ◽  
Svetlana A Paunović

Raspberry leaf blotch emaravirus (RLBV) is a recently characterised virus infecting raspberries reported in several European countries. RLBV causes yellow blotching, the distortion of leaf margins, and the twisting of raspberry leaves. For a long time, similar symptoms were attributed to the feeding damage caused by raspberry leaf and bud mite (Phyllocoptes gracilis). From 2014−2017, a large-scale survey was conducted in Serbia to investigate the degree of association of the observed symptoms with the RLBV infection. A total of 98 symptomatic and asymptomatic samples were collected from 30 locations. All collected samples were tested on the RLBV presence by reverse transcription and polymerase chain reaction (RT-PCR) using three sets of RNA-specific primers targeting RNA-1, RNA-3, and RNA-5 of the RLBV genome. RT-PCR analysis revealed high incidence of RLBV in tested samples (68.7%). RLBV was confirmed in raspberries ‘Fertödi Zamatos’, ‘Glen Ample’, ‘Meeker’, ‘Polana’, ‘Tulameen’ and ‘Willamette’. Twenty-one isolates were selected for sequencing the portion of the nucleocapsid (NC) gene. The nucleotide sequences of the isolates showed 93.2−100% identity. Phylogenetic analysis confirmed significant genetic variability of the Serbian RLBV isolates based on the nucleocapsid-encoding sequences and revealed the existence of two main clusters. Phylogenetic analysis of the 45 RLBV sequences from Finland, Slovakia, Scotland, and this study also confirmed the existence of two main clusters of isolates.


2006 ◽  
Vol 18 (2) ◽  
pp. 235
Author(s):  
S.-E. Lee ◽  
X.-Y. Li ◽  
X.-S. Cui ◽  
N.-H. Kim

Despite clear evidence of regulation of mitochondrial respiration by nuclear encoded genes, cytochrome oxidase (Cox), little information is available on their expression and functional roles during early embryonic development. To examine the role of Cox in oocyte maturation and embryogenesis, we first characterized mRNA and protein levels of nuclear encoded genes, Cox 5a, 5b, and 6b1, in mouse oocytes and during early embryogenesis, using real-time RT-PCR and immunocytochemistry. We then examined the possible role of these genes in oocyte maturation and pre-implantation development using RNA interference analysis. The relative abundances of Cox 5a, 5b, and 6b1 transcripts was measured by real time RT-PCR. After normalization by comparison to histone H2a mRNA levels, the mRNA expression of Cox 5a, 5b, and 6b1 were found to be considerable in mature oocytes and zygotes, but reduced slightly in 2-cell embryos. From the 2-cell to the blastocyst stage, mRNA expression is dependent on the number of blastomeres, as expression increases only gradually with development. Immunocytochemical studies revealed that Cox 5a, 5b, and 6b1 proteins were expressed in all blastomeres of the blastocyst. Injection of Cox 5a, 5b, or 6b1 siRNA into GV stage oocytes decreased expression of the target mRNA specifically, while not affecting the expression of mRNAs for the other subunits in mature oocytes. Similarly, each siRNA injection into zygotes specifically reduced target mRNA expression at the 2-cell, morula and blastocyst stages (P < 0.05). Silencing of mRNA expression by RNA interference (siRNA) did not inhibit oocyte maturation or developmental events up to the morula and blastocyst stages. The expression level of mtDNA9, as well as overall levels of mitochondrial mRNAs, was not different following injection of siRNA for Cox 5a, 5b, or 6b1. However, it is evident that the number of mitochondria in siRNA treated blastocysts was greatly reduced, and they appeared to be morphologically abnormal. Significantly higher apoptosis and lower cell numbers were observed in siRNA treated blastocysts. Real time RT PCR revealed that silencing of Cox 5a, 5b, and 6b1 decreased mRNA and protein levels of E-cadherin. These results suggest that the Cox subunits, Cox 5a, 5b, and 6b1, play an important role in mitochondrial function during pre-implantation development. This work was funded by a grant from the National Research Laboratory Program in Korea.


Author(s):  
Jia Huang ◽  
Shu-Jing Li ◽  
Xian-Hua Chen ◽  
Yu Han ◽  
Ping Xu

AbstractThis study focused on the function of hnRNP-R in the regulation of c-fos expression. We demonstrated that hnRNP-R accelerated the rise and decline phases of c-fos mRNAs and Fos proteins, allowing PMA to induce an augmented pulse response of c-fos expression. Then, we examined the role of the c-fos-derived AU-rich element (ARE) in hnRNP-R-regulated mRNA degradation. Studies with the ARE-GFP reporter gene showed that hnRNP-R significantly reduced the expression of GFP with an inserted ARE. Moreover, immunoprecipitation-RT-PCR analysis demonstrated that in R28 cells and rat retinal tissues, the c-fos mRNA was co-immunoprecipitated with hnRNP-R. These findings indicate that hnRNP-R regulates the c-fos expression in retinal cells, and that the ARE of c-fos mRNAs contributes to this regulation.


2014 ◽  
Vol 33 (11) ◽  
pp. 1176-1185 ◽  
Author(s):  
AK Pandurangan ◽  
P Dharmalingam ◽  
SKA Sadagopan ◽  
S Ganapasam

The present investigation deals with the antimetastatic role of luteolin (LUT) by inhibiting matrix metalloproteinase (MMP)-9 and -2 in azoxymethane (AOM)-induced colon carcinogenesis in Balb/C mice. Animals received AOM at a dosage of 15 mg/kg body weight intraperitoneally once a week for 3 weeks. AOM-induced mice was treated with LUT (1.2 mg of LUT/kg body weight/day orally). After the experimental period, the tumor markers such as γ-glutamyl transferase (GGT), 5′ nucleotidase (5′ND), cathepsin-D (Cat-D), and carcinoembroyonic antigen (CEA) were elevated upon induction with AOM. Subsequent treatment with LUT results in the reduction of the tumor markers was recorded. The expressions of MMP-9 and MMP-2 were analyzed by reverse transcription–polymerase chain reaction (RT-PCR) and immunofluorescence methods. The expressions of MMP-9 and MMP-2 were increased during AOM induction and upon treatment with LUT reduced the expressions. RT-PCR analysis of tissue inhibitor of matrix metalloproteinase ( TIMP)- 2 was limited during AOM-induced colorectal cancer (CRC). Supplementation of LUT increased the expression of TIMP-2. To conclude, LUT acts as an antimetastatic agent by suppressing MMP-9 and MMP-2 productions and upregulating TIMP-2 expression, thereby suggesting that LUT can be a chemotherapeutic agent against CRC.


2017 ◽  
Vol 44 (2) ◽  
pp. 505-514 ◽  
Author(s):  
Minghui Liu ◽  
Kai Yin ◽  
Xu Guo ◽  
Huijin Feng ◽  
Min Yuan ◽  
...  

Background/Aims: This study focused on the oncogenic role of Diphthamide biosynthesis 1 (DPH1) in colorectal cancer (CRC) cells. Methods: The expression of DPH1 was determined by quantitative RT-PCR analysis and western blotting in CRC tissues. The role of DPH1 in CRC cells was investigated via cell viability and invasion assays under the condition of DPH1 silencing or overexpression. Bioinformatics analysis and luciferase reporter analysis were used to identify the upstream microRNA which might regulate DPH1.The inverse correlation between the microRNA and DPH1 was also detected in CRC cells. Results: We identified an unexpected role for DPH1 as an oncogene in CRC cells. The tumour-suppressive miR-218-5p regulates DPH1 directly and negatively. Loss of miR-218-5p drives the oncogenic role of DPH1 in CRC cells. Conclusion: The modulation of DPH1 by miR-218-5p may be an important regulatory axis during CRCtumourigenesis.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Hiromi H. Ueda ◽  
Kiyotada Naitou ◽  
Hiroyuki Nakamori ◽  
Kazuhiro Horii ◽  
Takahiko Shiina ◽  
...  

AbstractThe central nervous system is involved in regulation of defaecation. It is generally considered that supraspinal regions control the spinal defaecation centre. However, signal transmission from supraspinal regions to the spinal defaecation centre is still unclear. In this study, we investigated the regulatory role of an anorexigenic neuropeptide, α-MSH, in the spinal defaecation centre in rats. Intrathecal administration of α-MSH to the L6-S1 spinal cord enhanced colorectal motility. The prokinetic effect of α-MSH was abolished by severing the pelvic nerves. In contrast, severing the colonic nerves or thoracic cord transection at the T4 level had no impact on the effect of α-MSH. RT-PCR analysis revealed MC1R mRNA and MC4R mRNA expression in the L6-S1 spinal cord. Intrathecally administered MC1R agonists, BMS470539 and SHU9119, mimicked the α-MSH effect, but a MC4R agonist, THIQ, had no effect. These results demonstrate that α-MSH binds to MC1R in the spinal defaecation centre and activates pelvic nerves, leading to enhancement of colorectal motility. This is, to our knowledge, the first report showing the functional role of α-MSH in the spinal cord. In conclusion, our findings suggest that α-MSH is a candidate for a neurotransmitter from supraspinal regions to the spinal defaecation centre.


2010 ◽  
Vol 59 (7) ◽  
pp. 797-803 ◽  
Author(s):  
Hao Zheng ◽  
Yuan-Ying Jiang ◽  
Yan Wang ◽  
Xin-Ming Jia ◽  
Tian-Hua Yan ◽  
...  

In this study the role of the TOP2 gene in fungal drug susceptibility was investigated by disrupting and overexpressing the gene in Candida albicans. MIC determination and a spot assay showed that a top2Δ/Δ null mutant (strain T2bc) was more resistant to the antifungals tested than the wild-type (strain CAI4). Real-time RT-PCR and rhodamine 6G efflux examination showed that TOP2 did not influence the activity of drug efflux pumps. Sterol analysis with GC/high-resolution MS indicated that the intracellular ergosterol composition of the top2Δ/Δ mutant was significantly increased. Subsequently, fluorescence polarization measurements also revealed that Top2-deprived cells displayed a decrease in membrane fluidity, resulting in enhanced passive diffusion of the drugs. Quantitative real-time RT-PCR analysis further confirmed that the ERG11 gene, an essential gene in ergosterol biosynthesis, was upregulated. These results demonstrate a close relationship between the TOP2 gene and drug susceptibility in C. albicans.


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