scholarly journals Ectopic Expressions of the GhLETM1 Gene Reveal Sensitive Dose Effects on Precise Stamen Development and Male Fertility in Cotton

Genes ◽  
2020 ◽  
Vol 11 (7) ◽  
pp. 772
Author(s):  
Li Zhang ◽  
Yao Zhang ◽  
Yijie Fan ◽  
Haixia Guo ◽  
Huihui Guo ◽  
...  
Keyword(s):  
Leucine Zipper ◽  
Ectopic Expression ◽  
Dose Effect ◽  
Practical Significance ◽  
Proper Function ◽  
Pollen Abortion ◽  
Stamen Development ◽  
Ef Hand ◽  
Accurate Expression ◽  
Eukaryotic Organisms

The homologous leucine zipper/EF-hand-containing transmembranes (LETMs) are highly conserved across a broad range of eukaryotic organisms. The LETM functional characteristics involved in biological process have been identified primarily in animals, but little is known about the LETM biological function mode in plants. Based on the results of the current investigation, the GhLETM1 gene crucially affects filament elongation and anther dehiscence of the stamen in cotton. Both excessive and lower expression of the GhLETM1 gene lead to defective stamen development, resulting in shortened filaments and indehiscent anthers with pollen abortion. The results also showed that the phenotype of the shortened filaments was negatively correlated with anther defects in the seesaw model under the ectopic expression of GhLETM1. Moreover, our results notably indicated that the gene requires accurate expression and exhibits a sensitive dose effect for its proper function. This report has important fundamental and practical significance in crop science, and has crucial prospects for genetic engineering of new cytoplasmic male sterility lines and breeding of crop hybrid varieties.

scholarly journals Functional Characterization of Spliceosomal Introns and Identification of U2, U4, and U5 snRNAs in the Deep-Branching Eukaryote Entamoeba histolytica

2007 ◽  
Vol 6 (6) ◽  
pp. 940-948 ◽  
Author(s):  
Carrie A. Davis ◽  
Michael P. S. Brown ◽  
Upinder Singh
Keyword(s):  
Entamoeba Histolytica ◽  
Splice Site ◽  
Expressed Sequence Tag ◽  
Functional Characterization ◽  
Molecular Evidence ◽  
Spliceosomal Introns ◽  
Accurate Expression ◽  
Eukaryotic Organisms

ABSTRACT Pre-mRNA splicing is essential to ensure accurate expression of many genes in eukaryotic organisms. In Entamoeba histolytica, a deep-branching eukaryote, approximately 30% of the annotated genes are predicted to contain introns; however, the accuracy of these predictions has not been tested. In this study, we mined an expressed sequence tag (EST) library representing 7% of amoebic genes and found evidence supporting splicing of 60% of the testable intron predictions, the majority of which contain a GUUUGU 5′ splice site and a UAG 3′ splice site. Additionally, we identified several splice site misannotations, evidence for the existence of 30 novel introns in previously annotated genes, and identified novel genes through uncovering their spliced ESTs. Finally, we provided molecular evidence for the E. histolytica U2, U4, and U5 snRNAs. These data lay the foundation for further dissection of the role of RNA processing in E. histolytica gene expression.

scholarly journals LATERAL FLORET 1 induced the three-florets spikelet in rice

2017 ◽  
Vol 114 (37) ◽  
pp. 9984-9989 ◽  
Author(s):  
Ting Zhang ◽  
Yunfeng Li ◽  
Ling Ma ◽  
Xianchun Sang ◽  
Yinghua Ling ◽  
...  
Keyword(s):  
Leucine Zipper ◽  
Molecular Mechanisms ◽  
Ectopic Expression ◽  
Target Sequence ◽  
Class Iii ◽  
Rice Mutant ◽  
Inflorescence Structure ◽  
Meristem Maintenance ◽  
Floral Meristems ◽  
Sterile Lemma

The spikelet is a unique inflorescence structure in grass. The molecular mechanisms behind the development and evolution of the spikelet are far from clear. In this study, a dominant rice mutant, lateral florets 1 (lf1), was characterized. In the lf1 spikelet, lateral floral meristems were promoted unexpectedly and could generally blossom into relatively normal florets. LF1 encoded a class III homeodomain-leucine zipper (HD-ZIP III) protein, and the site of mutation in lf1 was located in a putative miRNA165/166 target sequence. Ectopic expression of both LF1 and the meristem maintenance gene OSH1 was detected in the axil of the sterile lemma primordia of the lf1 spikelet. Furthermore, the promoter of OSH1 could be bound directly by LF1 protein. Collectively, these results indicate that the mutation of LF1 induces ectopic expression of OSH1, which results in the initiation of lateral meristems to generate lateral florets in the axil of the sterile lemma. This study thus offers strong evidence in support of the “three-florets spikelet” hypothesis in rice.

scholarly journals Restoration of stamen development and production of functional pollen in an alloplasmic CMS tobacco line by ectopic expression of the Arabidopsis thaliana SUPERMAN gene

2002 ◽  
Vol 29 (5) ◽  
pp. 607-615 ◽  
Author(s):  
Agnès Bereterbide ◽  
Michel Hernould ◽  
Isabelle Farbos ◽  
Kristina Glimelius ◽  
Armand Mouras
Keyword(s):  
Arabidopsis Thaliana ◽  
Ectopic Expression ◽  
Stamen Development ◽  
Superman Gene

scholarly journals SLC25A23 augments mitochondrial Ca2+ uptake, interacts with MCU, and induces oxidative stress–mediated cell death

2014 ◽  
Vol 25 (6) ◽  
pp. 936-947 ◽  
Author(s):  
Nicholas E. Hoffman ◽  
Harish C. Chandramoorthy ◽  
Santhanam Shanmughapriya ◽  
Xueqian Q. Zhang ◽  
Sandhya Vallem ◽  
...  
Keyword(s):  
Cell Death ◽  
Ectopic Expression ◽  
Dominant Negative ◽  
Inner Mitochondrial Membrane ◽  
Solute Carriers ◽  
Metabolic Functions ◽  
Evolutionarily Conserved ◽  
Ef Hand ◽  
Solute Carrier ◽  
Negative Phenotype

Emerging findings suggest that two lineages of mitochondrial Ca2+ uptake participate during active and resting states: 1) the major eukaryotic membrane potential–dependent mitochondrial Ca2+ uniporter and 2) the evolutionarily conserved exchangers and solute carriers, which are also involved in ion transport. Although the influx of Ca2+ across the inner mitochondrial membrane maintains metabolic functions and cell death signal transduction, the mechanisms that regulate mitochondrial Ca2+ accumulation are unclear. Solute carriers—solute carrier 25A23 (SLC25A23), SLC25A24, and SLC25A25—represent a family of EF-hand–containing mitochondrial proteins that transport Mg-ATP/Pi across the inner membrane. RNA interference–mediated knockdown of SLC25A23 but not SLC25A24 and SLC25A25 decreases mitochondrial Ca2+ uptake and reduces cytosolic Ca2+ clearance after histamine stimulation. Ectopic expression of SLC25A23 EF-hand–domain mutants exhibits a dominant-negative phenotype of reduced mitochondrial Ca2+ uptake. In addition, SLC25A23 interacts with mitochondrial Ca2+ uniporter (MCU; CCDC109A) and MICU1 (CBARA1) while also increasing IMCU. In addition, SLC25A23 knockdown lowers basal mROS accumulation, attenuates oxidant-induced ATP decline, and reduces cell death. Further, reconstitution with short hairpin RNA–insensitive SLC25A23 cDNA restores mitochondrial Ca2+ uptake and superoxide production. These findings indicate that SLC25A23 plays an important role in mitochondrial matrix Ca2+ influx.

scholarly journals Functional reconstitution of the mitochondrial Ca2+/H+ antiporter Letm1

2013 ◽  
Vol 143 (1) ◽  
pp. 67-73 ◽  
Author(s):  
Ming-Feng Tsai ◽  
Dawei Jiang ◽  
Linlin Zhao ◽  
David Clapham ◽  
Christopher Miller
Keyword(s):  
Transport Mechanism ◽  
Turnover Rate ◽  
Leucine Zipper ◽  
Transmembrane Protein ◽  
Ruthenium Red ◽  
Mitochondrial Calcium Uniporter ◽  
Mitochondrial Inner Membrane ◽  
Calcium Uniporter ◽  
Ef Hand ◽  
Inner Membrane Protein

The leucine zipper, EF hand–containing transmembrane protein 1 (Letm1) gene encodes a mitochondrial inner membrane protein, whose depletion severely perturbs mitochondrial Ca2+ and K+ homeostasis. Here we expressed, purified, and reconstituted human Letm1 protein in liposomes. Using Ca2+ fluorophore and 45Ca2+-based assays, we demonstrate directly that Letm1 is a Ca2+ transporter, with apparent affinities of cations in the sequence of Ca2+ ≈ Mn2+ > Gd3+ ≈ La3+ > Sr2+ >> Ba2+, Mg2+, K+, Na+. Kinetic analysis yields a Letm1 turnover rate of 2 Ca2+/s and a Km of ∼25 µM. Further experiments show that Letm1 mediates electroneutral 1 Ca2+/2 H+ antiport. Letm1 is insensitive to ruthenium red, an inhibitor of the mitochondrial calcium uniporter, and CGP-37157, an inhibitor of the mitochondrial Na+/Ca2+ exchanger. Functional properties of Letm1 described here are remarkably similar to those of the H+-dependent Ca2+ transport mechanism identified in intact mitochondria.

scholarly journals A Role for Groucho Tetramerization in Transcriptional Repression

1998 ◽  
Vol 18 (12) ◽  
pp. 7259-7268 ◽  
Author(s):  
Guoqing Chen ◽  
Pierre H. Nguyen ◽  
Albert J. Courey
Keyword(s):  
Transcriptional Repression ◽  
Fusion Proteins ◽  
Leucine Zipper ◽  
Point Mutations ◽  
Cross Linking ◽  
Transcriptional Repressors ◽  
Terminal Domain ◽  
Tetramerization Domain ◽  
Repeat Domain ◽  
Eukaryotic Organisms

ABSTRACT The Drosophila Groucho (Gro) protein is a corepressor required by a number of DNA-binding transcriptional repressors. Comparison of Gro with its homologues in other eukaryotic organisms reveals that Gro contains, in addition to a conserved C-terminal WD repeat domain, a conserved N-terminal domain, which has previously been implicated in transcriptional repression. We determined, via a variety of hydrodynamic measurements as well as protein cross-linking, that native Gro is a tetramer in solution and that tetramerization is mediated by two putative amphipathic α-helices (termed leucine zipper-like motifs) found in the N-terminal region. Point mutations in the leucine zipper-like motifs that block tetramerization also block repression by Gro, as assayed in cultured Drosophila cells with Gal4-Gro fusion proteins. Furthermore, the heterologous tetramerization domain from p53 fully substitutes for the Gro tetramerization domain in transcriptional repression. These findings suggest that oligomerization is essential for Gro-mediated repression and that the primary function of the conserved N-terminal domain is to mediate this oligomerization.

scholarly journals Leucine zipper-EF-hand containing transmembrane protein 1 (LETM1) forms a Ca2+/H+ antiporter

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Juan Shao ◽  
Zhenglin Fu ◽  
Yanli Ji ◽  
Xiangchen Guan ◽  
Shang Guo ◽  
...  
Keyword(s):  
Leucine Zipper ◽  
Transmembrane Protein ◽  
Ef Hand

scholarly journals Stress-Activated Degradation of Sphingolipids Regulates Mitochondrial Function and Cell Death in Yeast

2017 ◽  
Vol 2017 ◽  
pp. 1-14 ◽  
Author(s):  
Sara Manzanares-Estreder ◽  
Amparo Pascual-Ahuir ◽  
Markus Proft
Keyword(s):  
Cell Death ◽  
Mitochondrial Function ◽  
Ectopic Expression ◽  
Degradation Pathway ◽  
Sphingolipid Metabolism ◽  
Bax Protein ◽  
Consumption Rates ◽  
Genetic Interventions ◽  
Eukaryotic Organisms ◽  
Species Production

Sphingolipids are regulators of mitochondria-mediated cell death in higher eukaryotes. Here, we investigate how changes in sphingolipid metabolism and downstream intermediates of sphingosine impinge on mitochondrial function. We found in yeast that within the sphingolipid degradation pathway, the production via Dpl1p and degradation via Hfd1p of hexadecenal are critical for mitochondrial function and cell death. Genetic interventions, which favor hexadecenal accumulation, diminish oxygen consumption rates and increase reactive oxygen species production and mitochondrial fragmentation and vice versa. The location of the hexadecenal-degrading enzyme Hfd1p in punctuate structures all along the mitochondrial network depends on a functional ERMES (endoplasmic reticulum-mitochondria encounter structure) complex, indicating that modulation of hexadecenal levels at specific ER-mitochondria contact sites might be an important trigger of cell death. This is further supported by the finding that externally added hexadecenal or the absence of Hfd1p enhances cell death caused by ectopic expression of the human Bax protein. Finally, the induction of the sphingolipid degradation pathway upon stress is controlled by the Hog1p MAP kinase. Therefore, the stress-regulated modulation of sphingolipid degradation might be a conserved way to induce cell death in eukaryotic organisms.

scholarly journals Ectopic expression of finger millet calmodulin confers drought and salinity tolerance in Arabidopsis thaliana

2021 ◽  
Author(s):  
Gautam Jamra ◽  
Aparna Agrawal ◽  
Nidhi Singh ◽  
Sibaji K. Sanyal ◽  
Anil Kumar ◽  
...  
Keyword(s):  
Arabidopsis Thaliana ◽  
Stress Responses ◽  
Finger Millet ◽  
Ectopic Expression ◽  
Crop Productivity ◽  
Ion Leakage ◽  
In Planta ◽  
Wide Range ◽  
Ef Hand ◽  
Response To Stress

Abstract Drought and salinity are major environmental stresses which affect crop productivity and therefore are major hindrance in feeding growing population world-wide. Calcium (Ca2+) signalling plays a crucial role during the plant's response to these stress stimuli. Calmodulin (CaM), a crucial Ca2+sensor, is involved in transducing the signal downstream in various physiological, developmental and stress responses by modulating a plethora of target proteins. The role of CaM has been well established in the model plant Arabidopsis thaliana for regulating various developmental processes, stress signalling and ion transport. In the current study, we investigate the CaM of Eleusine coracana (common name finger millet, known especially for its drought tolerance and superior Ca2+ content). In-silico analysis showed that Eleucine calmodulin (EcCaM) has greater similarity to rice CaM as compared to Arabidopsis CaM due to the presence of highly conserved four EF-hand domains. To decipher the in planta function of EcCaM, we have adopted the gain-of-function approach by generating the 35S::EcCaM over-expression transgenic in Arabidopsis. Overexpression of EcCaM in Arabidopsis makes the plant tolerant to polyethylene glycol (PEG) induced drought and salt stress (NaCl) as demonstrated by post-germination based phenotypic assay, ion leakage, MDA and proline estimation, ROS detection under stressed and normal conditions. Moreover, EcCaM-overexpression leads to hypersensitivity towards exogenously applied ABA at the seed germination stage. These findings reveal that EcCaM mediates tolerance to drought and salinity stress. Also, our results indicate that EcCaM is involved in modulating ABA signalling. Summarizing our results, we report for the first time that EcCaM is involved in modulating plants response to stress and this information can be used for the generation of future-ready crops that can tolerate a wide range of abiotic stresses.

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