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氮磷饥饿诱导的水稻糖转运体基因的cDNA克隆和鉴定 总被引:2,自引:0,他引:2
运用快速扣除杂交 (RaSH)方法构建了水稻氮饥饿诱导的cDNA文库。从该文库获得了一个cDNA克隆OsNSI1 (Oryzasativanitrogenstarva tion inducible 1 )。该全长cDNA编码 5 77个氨基酸 ,蛋白分子量为 6 1 .2kD。推测得出的氨基酸序列与其他物种的糖转运体有很高的同源性。水合性分析表明OsNSI1包含有 1 2个跨膜区域和一个中心亲水环。这些数据提示OsNSI1是一个糖转运体蛋白。Southern印迹分析表明OsNSI1是一个单拷贝基因。Northern印迹分析表明OsNSI1主要在叶及根中表达 ,氮、磷饥饿能强烈诱导其表达增强 相似文献
3.
Andrea Bannert Kristina Kleineidam Livia Wissing Cornelia Mueller-Niggemann Vanessa Vogelsang Gerhard Welzl Zhihong Cao Michael Schloter 《Applied and environmental microbiology》2011,77(17):6109-6116
In many areas of China, tidal wetlands have been converted into agricultural land for rice cultivation. However, the consequences of land use changes for soil microbial communities are poorly understood. Therefore, we investigated bacterial and archaeal communities involved in inorganic nitrogen turnover (nitrogen fixation, nitrification, and denitrification) based on abundances and relative species richness of the corresponding functional genes along a soil chronosequence ranging between 50 and 2,000 years of paddy soil management compared to findings for a tidal wetland. Changes in abundance and diversity of the functional groups could be observed, reflecting the different chemical and physical properties of the soils, which changed in terms of soil development. The tidal wetland was characterized by a low microbial biomass and relatively high abundances of ammonia-oxidizing microbes. Conversion of the tidal wetlands into paddy soils was followed by a significant increase in microbial biomass. Fifty years of paddy management resulted in a higher abundance of nitrogen-fixing microbes than was found in the tidal wetland, whereas dominant genes of nitrification and denitrification in the paddy soils showed no differences. With ongoing rice cultivation, copy numbers of archaeal ammonia oxidizers did not change, while that of their bacterial counterparts declined. The nirK gene, coding for nitrite reductase, increased with rice cultivation time and dominated its functionally redundant counterpart, nirS, at all sites under investigation. Relative species richness showed significant differences between all soils with the exception of the archaeal ammonia oxidizers in the paddy soils cultivated for 100 and 300 years. In general, changes in diversity patterns were more pronounced than those in functional gene abundances. 相似文献
4.
Jiong-Ming Sui Bao-Tai Guo Jing-Shan Wang Li-Xian Qiao Yong Zhou Hong-Gen Zhang Ming-Hong Gu Guo-Hua Liang 《Plant Molecular Biology Reporter》2012,30(1):187-194
A semidwarf line of Indica rice, Xinguiai, was derived from the progeny of a cross between the double dwarf mutant Xinguiaishuangai and the wild-type
variety Nanjing 6. The semidwarf phenotype was controlled by the semidwarf gene, sdg. The second sheath and shoot elongation responses of the dwarf mutant to exogenous gibberellin (GA3) showed that sdg was insensitive to gibberellin (GA), and its endogenous GAs content was higher than that in wild-type cultivars. The SDG gene was cloned by a map-based cloning method and sequencing analysis revealed that the coding region of sdg had a single nucleotide substitution resulting in a single amino acid change from alanine to threonine. A cleaved amplified
polymorphic sequence marker was designed according to sequences from mutant and wild-type materials. This sequence marker
could be used to distinguish wild types and mutants, and thus, could be used for molecular marker-assisted selection. The
dwarf phenotype of the sdg mutant was restored to a normal phenotype by introducing the wild-type SDG gene. Rice transformation experiments and GUS staining demonstrated that the SDG gene was predominantly expressed in vegetative organs. 相似文献
5.
Michel Schalk Francisco Cabello-Hurtado Marie-Agnès Pierrel Rossitza Atanossova Patrick Saindrenan Danièle Werck-Reichhart 《Plant physiology》1998,118(1):209-218
Piperonylic acid (PA) is a natural
molecule bearing a methylenedioxy function that closely mimics the
structure of trans-cinnamic acid. The CYP73A subfamily
of plant P450s catalyzes trans-cinnamic acid
4-hydroxylation, the second step of the general phenylpropanoid
pathway. We show that when incubated in vitro with yeast-expressed
CYP73A1, PA behaves as a potent mechanism-based and quasi-irreversible
inactivator of trans-cinnamate 4-hydroxylase.
Inactivation requires NADPH, is time dependent and saturable
(KI = 17 μm,
kinact = 0.064 min−1), and
results from the formation of a stable metabolite-P450 complex
absorbing at 427 nm. The formation of this complex is reversible with
substrate or other strong ligands of the enzyme. In plant microsomes PA
seems to selectively inactivate the CYP73A P450 subpopulation. It does
not form detectable complexes with other recombinant plant P450
enzymes. In vivo PA induces a sharp decrease in 4-coumaric acid
concomitant to cinnamic acid accumulation in an elicited tobacco
(Nicotiana tabacum) cell suspension. It also strongly
decreases the formation of scopoletin in tobacco leaves infected with
tobacco mosaic virus.The phenylpropanoid metabolism is a plant-specific pathway leading
to compounds of extremely diverse structure and function (Dixon and
Paiva, 1995; Werck-Reichhart, 1995). It is involved in the formation of
quantitatively major biopolymers such as lignin and suberin, but also
in the biosynthesis of signaling molecules such as salicylic acid and
isoflavonoids in flower pigments, UV protectants such as anthocyanins,
flavonoids, and coumarins, and several classes of phytoalexins. The
upstream part of the phenylpropanoid metabolism, which branches from
the shikimate pathway at the level of l-Phe, consists of a
core of three enzymatic steps leading to 4-coumaroyl CoA (Fig.
(Fig.1).1). This set of three reactions, often
called the general phenylpropanoid pathway, controls the flux of
metabolites toward all families of compounds derived from the C6-C3
skeleton of Phe. Compounds with a C6-C1 structure are not strictly
phenylpropanoids, but also derive from l-Phe. They
originate from the core pathway intermediates cinnamic acid or
4-coumaric acid (Yalpani et al., 1993). Molecules with a C6-C1 backbone
include benzoic and salicylic acids and economically important
compounds such as vanillin.
Figure 1Branching and inhibitors of the phenylpropanoid
pathway. AOPP, α-Amino-β-phenylpropionic acid; MDCA,
methylenedioxycinnamic acid.The second step in the core phenylpropanoid pathway is the
hydroxylation of trans-cinnamic acid to 4-coumaric acid. The
reaction is catalyzed by C4H, a member of the superfamily of Cyt P450
heme-thiolate proteins. P450s are monooxygenases that catalyze the
oxidation of a remarkably broad range of endogenous and exogenous
chemicals in all organisms. In plants they play important roles in
biosynthetic pathways, including those of sterols, isoprenoids,
alkaloids, oxygenated fatty acids, and phenylpropanoids (Bolwell et
al., 1994; Durst and O''Keefe, 1995; Schuler, 1996). They are also
involved in the metabolism and sometimes in the activation of many
herbicides, insecticides, and other xenobiotics. CYP73A1 is a C4H from
Jerusalem artichoke (Helianthus tuberosus). Its coding
sequence was isolated from tuber tissues (Teutsch et al., 1993) and
expressed in yeast (Urban et al., 1994). The yeast-expressed enzyme is
catalytically active and capable of hydroxylating cinnamic acid with a
very high efficiency (kcat ranging from 100
to 400 min−1).The high activity of the recombinant enzyme led us to investigate its
activity toward other potential substrates, natural plant components,
and xenobiotics. Several exogenous molecules were thus found to be
substrates of CYP73A1 (Pierrel et al., 1994; Schalk et al., 1997). The
efficiency of the metabolism of the xenobiotic molecules largely relied
on their structural analogy to the natural substrate. A systematic
structure-activity study recently led to the characterization of some
good alternative substrates and high-affinity inhibitors of the enzyme,
and of the structural requirements for an efficient binding into the
active site of CYP73A1 (Schalk et al., 1997). The ideal ligand of C4H
was thus defined as a rigid hydrophobic backbone of the size of a
bicyclic aromatic structure (e.g. naphthalene), bearing one or several
small negatively charged substituent(s) centered around carbon 2 of the
naphthalene ring, the prototype alternative substrate being 2-naphthoic
acid (Fig. (Fig.2).
2).
Figure 2Structural analogy between substrates of
CYP73A1.PA is a natural molecule extracted from the bark of the Paracoto tree
that roughly fulfills all of these requirements. PA contains a MDP
function at a position suitable for oxidative attack by CYP73A1. Many
compounds with MDP function have been shown to inhibit mammalian or
insect P450 enzymes both in vitro and in vivo (Franklin, 1977;
Wilkinson et al., 1984; Ortiz de Montellano and Correia, 1995). They
were shown to act as mechanism-based inactivators and to require
P450-catalyzed metabolism to generate a MI forming a stable complex
with the enzyme (Franklin, 1971). Available data suggest that the MI is
likely a carbene that binds as the sixth coordinant to the heme iron
(Mansuy et al., 1979).We have tested PA inhibition of recombinant CYP73A1 and show that it
behaves as a very potent, mechanism-based inhibitor of C4H. It is
effective in vitro on the recombinant enzyme, being far more efficient
than other MDP compounds. It is apparently selective for C4H. Assays
performed in vivo on tobacco (Nicotiana tabacum) leaves and
cell cultures indicate that it can be used to inactivate C4H and to
block the input of precursors into the main C6-C3 pathway. To our
knowledge, it is the first selective and quasi-irreversible inhibitor
of the C4H so far described. 相似文献
6.
Dongwei Hui Keshava N. Kumar Julie R. Mach Ashik Srinivasan Ranu Pal Xiaodong Bao Abdulbaki Agbas Georg H?fner Klaus T. Wanner Elias K. Michaelis 《The Journal of biological chemistry》2009,284(4):2245-2257
The cloning and characterization of the gene for the fourth subunit of a
glutamate-binding protein complex in rat brain synaptic membranes are
described. The cloned rat brain cDNA contained two open reading frames (ORFs)
encoding 8.9- (PRO1) and 9.5-kDa (PRO2) proteins. The cDNA sequence matched
contiguous genomic DNA sequences in rat chromosome 17. Both ORFs were
expressed within the structure of a single brain mRNA and antibodies against
unique sequences in PRO1- and PRO2-labeled brain neurons in situ,
indicative of bicistronic gene expression. Dicistronic vectors in which ORF1
and ORF2 were substituted by either two different fluorescent proteins or two
luciferases indicated concurrent, yet independent translation of the two ORFs.
Transfection with noncapped mRNA led to cap-independent translation of only
ORF2 through an internal ribosome entry sequence preceding ORF2. In
vitro or cell expression of the cloned cDNA led to the formation of
multimeric protein complexes containing both PRO1 and PRO2. These complexes
had low affinity
(+)-5-methyl-10,11-dihydro-5H-dibenzo[a,d]cyclohepten-5,10-imine
(MK-801)-sensitive phencyclidine-binding sites. Overexpression of PRO1 and
PRO2 in CHO cells, but not neuroblastoma cells, caused cell death within
24–48 h. The cytotoxicity was blocked by concurrent treatment with
MK-801 or by two tetrahydroisoquinolines that bind to phencyclidine sites in
neuronal membranes. Co-expression of two of the other subunits of the protein
complex together with PRO1/PRO2 abrogated the cytotoxic effect without
altering PRO1/PRO2 protein levels. Thus, this rare mammalian bicistronic gene
coded for two tightly interacting brain proteins forming a low affinity
phencyclidine-binding entity in a synaptic membrane complex.A complex of four proteins purified from brain synaptic membranes was shown
to have recognition sites for l-glutamate,
N-methyl-d-aspartate
(NMDA),4 and other
ligands characteristic of NMDA receptors in brain, including binding sites for
the co-agonist glycine, the modulator spermine, the competitive antagonist
(+)-3-(2-carboxypiperazin-4-yl)-propyl-1-phosphonic acid (CPP), and the ion
channel inhibitors thienylcyclohexylpiperidine (TCP) and
(+)-5-methyl-10,11-dihydro-5H-dibenzo[a,d]cyclohepten-5,10-imine
(MK-801) (1,
2). Reconstitution of the
purified complex into planar lipid bilayer membranes leads to the formation of
channels with four ion conductance levels upon activation by glutamate or NMDA
in the presence of glycine (3).
These conductances differ from either the predominant NMDA-activated
receptor-ion channels of brain neurons or those formed by reconstitution of
the NMDA receptor subunits (4),
but are similar to those described for ion channels in rat spinal cord motor
neurons (5).The genes for three of the proteins in this complex have been cloned and
expressed in heterologous cells
(6–10).
The gene GRINA for the glutamate-binding protein (GBP) subunit was
identified as part of a “learning and memory” module of genes
expressed in the entorhinal cortex of the mammalian brain
(11), and as the gene
responsible for mental retardation and epilepsy in infants with a gene
duplication in chromosome 8q24.3
(12). Expression of
GRINA in heterologous cells leads to activation of mitogen-activated
protein kinases (13),
i.e. it may be involved in signal transduction in neurons. Because of
the potential role of GBP and of the associated membrane complex in cell
signaling, there is a need to fully characterize all components of the complex
and reconstitute the intact complex in cells lacking in its expression. The
genes for two other components of the complex have been cloned, those for the
glycine-binding and CPP-binding proteins. But the gene for the fourth subunit
has not yet been cloned.The fourth protein of the complex was identified on SDS-PAGE as an
∼40-kDa protein. To complete the characterization of this complex of
proteins, the cDNA for the fourth subunit was cloned, and a corresponding
genomic sequence in rat genome was identified. The presence of two open
reading frames (ORFs) in the cloned cDNA, the expression of both ORFs in a
single mRNA in brain, and the translation in brain of the two proteins coded
by the cDNA, led to the investigation of the mechanism of translation of both
ORFs. Translation of both ORFs through an internal ribosome entry sequence
(IRES) was identified, as was the need for the co-expression of the two
proteins to create a functional protein, a phencyclidine-binding protein. 相似文献
7.
Lan L Chen W Lai Y Suo J Kong Z Li C Lu Y Zhang Y Zhao X Zhang X Zhang Y Han B Cheng J Xue Y 《Plant molecular biology》2004,54(4):471-487
To monitor gene expression profiles during pollination and fertilization in rice at a genome scale, we generated 73,424 high-quality expressed sequence tags (ESTs) derived from the green/etiolated shoot and pistil (0-5 h after pollination, 5hP) of rice, which were subsequently used to construct a cDNA microarray containing ca. 10 000 unique rice genes. This microarray was used to analyze gene expression in pistil unpollinated (UP), 5hP and 5DAP(5 days after pollination), anther, shoot, root, 10-day-old embryo (10EM) and 10-day-old endosperm (10EN). Clustering analysis revealed that the anther has a gene-expression profile more similar to root than to pistil and most pistil-preferentially expressed genes respond to pollination and/or fertilization. There are 253 ESTs exhibiting differential expression (e +/- 2-fold changes) during pollination and fertilization, and about 70% of them can be assigned a putative function. We also recovered 20 genes similar to pollination-related and/or fertility-related genes previously identified as well as genes that were not implicated previously. Microarray and real-time PCR analyses showed that the array sensitivity was estimated at 1-5 copies of mRNA per cell, and the differentially expressed genes showed a high correlation between the two methods. Our results indicated that this cDNA microarray constructed here is reliable and can be used for monitoring gene expression profiles in rice. In addition, the genes that differentially expressed during pollination represent candidate genes for dissecting molecular mechanism of this important biological process in rice. 相似文献
8.
Deborah G. Murdock Yuki Bradford Nathalie Schnetz-Boutaud Ping Mayo Melissa J. Allen Laura N. D’Aoust Xueying Liang Sabrina L. Mitchell Stephan Zuchner Gary W. Small John R. Gilbert Margaret A. Pericak-Vance Jonathan L. Haines 《PloS one》2013,8(12)
Alzheimer disease (AD) is a devastating neurodegenerative disease affecting more than five million Americans. In this study, we have used updated genetic linkage data from chromosome 10 in combination with expression data from serial analysis of gene expression to choose a new set of thirteen candidate genes for genetic analysis in late onset Alzheimer disease (LOAD). Results in this study identify the KIAA1462 locus as a candidate locus for LOAD in APOE4 carriers. Two genes exist at this locus, KIAA1462, a gene associated with coronary artery disease, and “rokimi”, encoding an untranslated spliced RNA The genetic architecture at this locus suggests that the gene product important in this association is either “rokimi”, or a different isoform of KIAA1462 than the isoform that is important in cardiovascular disease. Expression data suggests that isoform f of KIAA1462 is a more attractive candidate for association with LOAD in APOE4 carriers than “rokimi” which had no detectable expression in brain. 相似文献
9.
Benoit Morel Alexey M Kozlov Alexandros Stamatakis Gergely J Szllsi 《Molecular biology and evolution》2020,37(9):2763
Inferring phylogenetic trees for individual homologous gene families is difficult because alignments are often too short, and thus contain insufficient signal, while substitution models inevitably fail to capture the complexity of the evolutionary processes. To overcome these challenges, species-tree-aware methods also leverage information from a putative species tree. However, only few methods are available that implement a full likelihood framework or account for horizontal gene transfers. Furthermore, these methods often require expensive data preprocessing (e.g., computing bootstrap trees) and rely on approximations and heuristics that limit the degree of tree space exploration. Here, we present GeneRax, the first maximum likelihood species-tree-aware phylogenetic inference software. It simultaneously accounts for substitutions at the sequence level as well as gene level events, such as duplication, transfer, and loss relying on established maximum likelihood optimization algorithms. GeneRax can infer rooted phylogenetic trees for multiple gene families, directly from the per-gene sequence alignments and a rooted, yet undated, species tree. We show that compared with competing tools, on simulated data GeneRax infers trees that are the closest to the true tree in 90% of the simulations in terms of relative Robinson–Foulds distance. On empirical data sets, GeneRax is the fastest among all tested methods when starting from aligned sequences, and it infers trees with the highest likelihood score, based on our model. GeneRax completed tree inferences and reconciliations for 1,099 Cyanobacteria families in 8 min on 512 CPU cores. Thus, its parallelization scheme enables large-scale analyses. GeneRax is available under GNU GPL at https://github.com/BenoitMorel/GeneRax (last accessed June 17, 2020). 相似文献
10.
11.
Rebecca S. Bart Mawsheng Chern Miguel E. Vega-Sánchez Patrick Canlas Pamela C. Ronald 《PLoS genetics》2010,6(9)
Rice NH1 (NPR1 homolog 1) is a key mediator of innate immunity. In both plants and animals, the innate immune response is often accompanied by rapid cell death at the site of pathogen infection. Over-expression of NH1 in rice results in resistance to the bacterial pathogen, Xanthomonas oryzae pv. oryzae (Xoo), constitutive expression of defense related genes and enhanced benzothiadiazole (BTH)- mediated cell death. Here we describe a forward genetic screen that identified a suppressor of NH1-mediated lesion formation and resistance, snl6. Comparative genome hybridization and fine mapping rapidly identified the genomic location of the Snl6 gene. Snl6 is a member of the cinnamoyl-CoA reductase (CCR)-like gene family. We show that Snl6 is required for NH1-mediated resistance to Xoo. Further, we show that Snl6 is required for pathogenesis-related gene expression. In contrast to previously described CCR family members, disruption of Snl6 does not result in an obvious morphologic phenotype. Snl6 mutants have reduced lignin content and increased sugar extractability, an important trait for the production of cellulosic biofuels. These results suggest the existence of a conserved group of CCR-like genes involved in the defense response, and with the potential to alter lignin content without affecting development. 相似文献
12.
13.
Late embryogenesis abundant (LEA) proteins are involved in tolerance to drought, cold and high salinity in many different organisms. In this report, a LEA protein producing full-length gene OsLEA3-2 was identified in rice (Oryza sativa) using the Rapid Amplification of cDNA Ends (RACE) method. OsLEA3-2 was found to be only expressed in the embryo and can be induced by abiotic stresses. The coding protein localizes to the nucleus and overexpression of OsLEA3-2 in yeast improved growth performance compared with control under salt- and osmotic-stress conditions. OsLEA3-2 was also inserted into pHB vector and overexpressed in Arabidopsis and rice. The transgenic Arabidopsis seedlings showed better growth on MS media supplemented with 150 mM mannitol or 100 mM NaCl as compared with wild type plants. The transgenic rice also showed significantly stronger growth performance than control under salinity or osmotic stress conditions and were able to recover after 20 days of drought stress. In vitro analysis showed that OsLEA3-2 was able to protect LDH from aggregation on freezing and inactivation on desiccation. These results indicated that OsLEA3-2 plays an important role in tolerance to abiotic stresses. 相似文献
14.
Avian genomes are small and lack some genes that are conserved in the genomes of most other vertebrates including nonavian sauropsids. One hypothesis stated that paralogs may provide biochemical or physiological compensation for certain gene losses; however, no functional evidence has been reported to date. By integrating evolutionary analysis, physiological genomics, and experimental gene interference, we clearly demonstrate functional compensation for gene loss. A large-scale phylogenetic analysis of over 1,400 SLC2 gene sequences identifies six new SLC2 genes from nonmammalian vertebrates and divides the SLC2 gene family into four classes. Vertebrates retain class III SLC2 genes but partially lack the more recent duplicates of classes I and II. Birds appear to have completely lost the SLC2A4 gene that encodes an important insulin-sensitive GLUT in mammals. We found strong evidence for positive selection, indicating that the N-termini of SLC2A4 and SLC2A12 have undergone diversifying selection in birds and mammals, and there is a significant correlation between SLC2A12 functionality and basal metabolic rates in endotherms. Physiological genomics have uncovered that SLC2A12 expression and allelic variants are associated with insulin sensitivity and blood glucose levels in wild birds. Functional tests have indicated that SLC2A12 abrogation causes hyperglycemia, insulin resistance, and high relative activity, thus increasing energy expenditures that resemble a diabetic phenotype. These analyses suggest that the SLC2A12 gene not only functionally compensates insulin response for SLC2A4 loss but also affects daily physical behavior and basal metabolic rate during bird evolution, highlighting that older genes retain a higher level of functional diversification. 相似文献
15.
Carlos F. G. C. Geraldes Shanrong Zhang A. Dean Sherry 《Bioinorganic Chemistry and Applications》2003,1(1):1-23
Analysis of the LIS data for several series of Ln3+ complexes of C4 symmetry in terms of structural
changes, crystal-field effects and/or variation of hyperfine constants along the lanthanide series was
undertaken using a combination of the two-nuclei and three-nuclei techniques together with the classical onenucleus
technique. Isostructurality of whole series of complexes, with changes of the Fi, and B02 parameters,
was clearly defined for the complexes of L by the combination of the two first methods. Small changes,
involving the three Fi, Gi and B02 parameters, are observed for the series of complexes of L-L4, using the
three data plotting methods. Some of the plots according to the two- and three-nuclei methods are
accidentally linear, without necessarily implying isostructurality of the complexes, as they involve
parameters, which may be insensitive to any small structural changes occurring in these systems. These
parameter variations could result from a magnification, by the present graphical analysis, of the breaks
expected from the gradual structural changes along the series due to the lanthanide contraction. The α and β
parameters of the three-nuclei method are not diagnostic of the type of structures the complexes have in
solution, due to their very indirect dependence on the geometric factors. 相似文献
16.
Mitochondria are affected by low temperature during seedling establishment in maize (Zea mays L.). We evaluated the associated changes in the mitochondrial properties of populations selected for high (C4-H) and low (C4-L) germination levels at 9.5°C. When seedlings of the two populations were grown at 14°C (near the lower growth limit), the mitochondrial inner membranes of C4-H showed a higher percentage of 18-carbon unsaturated fatty acids, a higher fluidity, and a higher activity of cytochrome c oxidase. We found a positive relationship between these properties and the activity of a mitochondrial peroxidase, allowing C4-H to reduce lipid peroxidation relative to C4-L. The specific activity of reconstituted ATP/ADP translocase was positively associated with this peroxidase activity, suggesting that translocase activity is also affected by chilling. The level of oxidative stress and defense mechanisms are differently expressed in tolerant and susceptible populations when seedlings are grown at a temperature near the lower growth limit. Thus, the interaction between membrane lipids and cytochrome c oxidase seems to play a key role in maize chilling tolerance. Furthermore, the divergent-recurrent selection procedure apparently affects the allelic frequencies of genes controlling such an interaction. 相似文献
17.
18.
Brianna Norris-Mullins Kaitlin VanderKolk Paola Vacchina Michelle V. Joyce Miguel A. Morales 《PLoS neglected tropical diseases》2014,8(1)
We have identified LmaPA2G4, a homolog of the human proliferation-associated 2G4 protein (also termed Ebp1), in a phosphoproteomic screening. Multiple sequence alignment and cluster analysis revealed that LmaPA2G4 is a non-peptidase member of the M24 family of metallopeptidases. This pseudoenzyme is structurally related to methionine aminopeptidases. A null mutant system based on negative selection allowed us to demonstrate that LmaPA2G4 is an essential gene in Leishmania major. Over-expression of LmaPA2G4 did not alter cell morphology or the ability to differentiate into metacyclic and amastigote stages. Interestingly, the over-expression affected cell proliferation and virulence in mouse footpad analysis. LmaPA2G4 binds a synthetic double-stranded RNA polyriboinosinic polyribocytidylic acid [poly(I∶C)] as shown in an electrophoretic mobility shift assay (EMSA). Quantitative proteomics revealed that the over-expression of LmaPA2G4 led to accumulation of factors involved in translation initiation and elongation. Significantly, we found a strong reduction of de novo protein biosynthesis in transgenic parasites using a non-radioactive metabolic labeling assay. In conclusion, LmaPA2G4 is an essential gene and is potentially implicated in fundamental biological mechanisms, such as translation, making it an attractive target for therapeutic intervention. 相似文献
19.
20.
Takayuki Yokoo Hiroki Saito Yoshihiro Yoshitake Quan Xu Takehito Asami Takuji Tsukiyama Masayoshi Teraishi Yutaka Okumoto Takatoshi Tanisaka 《PloS one》2014,9(4)
Floral transition from the vegetative to the reproductive growth phase is a major change in the plant life cycle and a key factor in reproductive success. In rice (Oryza sativa L.), a facultative short-day plant, numerous flowering time and flower formation genes that control floral transition have been identified and their physiological effects and biochemical functions have been clarified. In the present study, we used a Se14-deficient mutant line (HS112) and other flowering mutant lines to investigate the photoperiodic response, chromosomal location and function in the photoperiod sensitivity of the Se14 gene. We also studied the interactive effects of this locus with other crucial flowering time genes. We found that Se14 is independent of the known photoperiod-sensitive genes, such as Hd1 and Ghd7, and is identical to Os03g0151300, which encodes a Jumonji C (JmjC) domain-containing protein. Expression analysis revealed that the expressions of RFT1, a floral initiator known as a “florigen-like gene”, and Ehd1 were up-regulated in HS112, whereas this up-regulation was not observed in the original variety of ‘Gimbozu’. ChIP assays of the methylation states of histone H3 at lysine 4 (H3K4) revealed that the trimethylated H3K4 in the promoter region of the RFT1 chromatin was significantly increased in HS112. We conclude that Se14 is a novel photoperiod-sensitivity gene that has a suppressive effect on floral transition (flowering time) under long day-length conditions through the modification of chromatin structure by H3K4me3 demethylation in the promoter region of RFT1. 相似文献