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101.
102.
Precocious flowering of juvenile citrus induced by a viral vector based on Citrus leaf blotch virus: a new tool for genetics and breeding 总被引:1,自引:0,他引:1 下载免费PDF全文
Karelia Velázquez Jesús Agüero María C. Vives Pablo Aleza José A. Pina Pedro Moreno Luis Navarro José Guerri 《Plant biotechnology journal》2016,14(10):1976-1985
The long juvenile period of citrus trees (often more than 6 years) has hindered genetic improvement by traditional breeding methods and genetic studies. In this work, we have developed a biotechnology tool to promote transition from the vegetative to the reproductive phase in juvenile citrus plants by expression of the Arabidopsis thaliana or citrus FLOWERING LOCUS T (FT) genes using a Citrus leaf blotch virus‐based vector (clbvINpr‐AtFT and clbvINpr‐CiFT, respectively). Citrus plants of different genotypes graft inoculated with either of these vectors started flowering within 4–6 months, with no alteration of the plant architecture, leaf, flower or fruit morphology in comparison with noninoculated adult plants. The vector did not integrate in or recombine with the plant genome nor was it pollen or vector transmissible, albeit seed transmission at low rate was detected. The clbvINpr‐AtFT is very stable, and flowering was observed over a period of at least 5 years. Precocious flowering of juvenile citrus plants after vector infection provides a helpful and safe tool to dramatically speed up genetic studies and breeding programmes. 相似文献
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Neylen Del Toro Ana Fernandez-Ruiz Lian Mignacca Paloma Kalegari Marie-Camille Rowell Sebastian Igelmann 《Cell cycle (Georgetown, Tex.)》2019,18(6-7):759-770
Senescence is a tumor suppressor program characterized by a stable growth arrest while maintaining cell viability. Senescence-associated ribogenesis defects (SARD) have been shown to regulate senescence through the ability of the ribosomal protein S14 (RPS14 or uS11) to bind and inhibit the cyclin-dependent kinase 4 (CDK4). Here we report another ribosomal protein that binds and inhibits CDK4 in senescent cells: L22 (RPL22 or eL22). Enforcing the expression of RPL22/eL22 is sufficient to induce an RB and p53-dependent cellular senescent phenotype in human fibroblasts. Mechanistically, RPL22/eL22 can interact with and inhibit CDK4-Cyclin D1 to decrease RB phosphorylation both in vitro and in cells. Briefly, we show that ribosome-free RPL22/eL22 causes a cell cycle arrest which could be relevant during situations of nucleolar stress such as cellular senescence or the response to cancer chemotherapy. 相似文献
105.
Barbara Tllez‐Robledo Concepcion Manzano Angela Saez Sara Navarro‐Neila Javier Silva‐Navas Laura de Lorenzo Mary‐Paz Gonzlez‐García Ren Toribio Arthur G. Hunt Roberto Baigorri Ilda Casimiro Siobhan M. Brady M. Mar Castellano J. Carlos del Pozo 《The Plant journal : for cell and molecular biology》2019,99(6):1203-1219
106.
Juan D. Franco‐Navarro Miguel A. Rosales Paloma Cubero‐Font Purificacin Calvo Rosario lvarez Antonio Diaz‐Espejo Jos M. Colmenero‐Flores 《The Plant journal : for cell and molecular biology》2019,99(5):815-831
Chloride (Cl?) has been recently described as a beneficial macronutrient, playing specific roles in promoting plant growth and water‐use efficiency (WUE). However, it is still unclear how Cl? could be beneficial, especially in comparison with nitrate (NO3?), an essential source of nitrogen that shares with Cl? similar physical and osmotic properties, as well as common transport mechanisms. In tobacco plants, macronutrient levels of Cl? specifically reduce stomatal conductance (gs) without a concomitant reduction in the net photosynthesis rate (AN). As stomata‐mediated water loss through transpiration is inherent in the need of C3 plants to capture CO2, simultaneous increase in photosynthesis and WUE is of great relevance to achieve a sustainable increase in C3 crop productivity. Our results showed that Cl?‐mediated stimulation of larger leaf cells leads to a reduction in stomatal density, which in turn reduces gs and water consumption. Conversely, Cl? improves mesophyll diffusion conductance to CO2 (gm) and photosynthetic performance due to a higher surface area of chloroplasts exposed to the intercellular airspace of mesophyll cells, possibly as a consequence of the stimulation of chloroplast biogenesis. A key finding of this study is the simultaneous improvement of AN and WUE due to macronutrient Cl? nutrition. This work identifies relevant and specific functions in which Cl? participates as a beneficial macronutrient for higher plants, uncovering a sustainable approach to improve crop yield. 相似文献
107.
Goñi-Oliver P Lucas JJ Avila J Hernández F 《The Journal of biological chemistry》2007,282(31):22406-22413
Although GSK-3 activity can be regulated by phosphorylation and through interaction with GSK-3-binding proteins, here we describe N-terminal proteolysis as a novel way to regulate GSK-3. When brain extracts were exposed to calcium, GSK-3 was truncated, generating two fragments of approximately 40 and 30 kDa, a proteolytic process that was inhibited by specific calpain inhibitors. Interestingly, instead of inhibiting this enzyme, GSK-3 truncation augmented its kinase activity. When we digested recombinant GSK-3 alpha and GSK-3beta protein with calpain, each isoform was cleaved differently, yet the truncated GSK-3 isoforms were still active kinases. We also found that lithium, a GSK-3 inhibitor, inhibits full-length and cleaved GSK-3 isoforms with the same IC(50) value. Calpain removed the N-terminal ends of His-tagged GSK-3 isoenzymes, and exposing cultured cortical neurons with ionomycin, glutamate, or N-methyl-d-aspartate led to the truncation of GSK-3. This truncation was blocked by the calpain inhibitor calpeptin, at the same concentration at which it inhibits calpain-mediated cleavage of NMDAR-2B and of p35 (the regulatory subunit of CDK5). Together, our data demonstrate that calpain activation produces a truncation of GSK-3 that removes an N-terminal inhibitory domain. Furthermore, we show that GSK-3 alpha and GSK-3beta isoenzymes have a different susceptibility to this cleavage, suggesting a means to specifically regulate these isoenzymes. These data provide the first direct evidence that calpain promotes GSK-3 truncation in a way that has implications in signal transduction, and probably in pathological disorders such as Alzheimer disease. 相似文献
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Ponce-Soto LA Bonfim VL Novello JC Navarro Oviedo R Yarlequé Chocas A Marangoni S 《The protein journal》2007,26(6):387-394
A serine protease from Bothrops
atrox (Peruvian specimen’s venom) was isolated in two chromatographic steps in LC molecular exclusion and reverse phase-HPLC. This
protein was denominated Ba III-4 (33,080.265 Da determinated by MALDI-TOF mass spectrometry) and showed pI of 5.06, Km 0.2 × 10−1
M and the V
máx 4.1 × 10−1 nmoles p-NA/lt/min on the synthetic substrate BapNA. Ba III-4 also showed ability to coagulate bovine fibrinogen. The serine
protease was inhibited by soyben trypsin inhibitor and DA2II, which is an anti-hemorrhagic factor isolated from the opossum
specie Didelphis albiventris. The primary structure of Ba III-4 showed the presence of His(44), Asp(94) and Ser(193) residues in the corresponding positions
to the catalytic triad established in the serine proteases and Ser(193) are inhibited by phenylmethylsulfonylfluoride (PMSF).
Amino acid analysis showed a high content of Asp, Glu, Gly, Ser, Ala and Pro, as well as 12 half-cysteine residues. Ba III-4
contained 293 amino acid residues and the primary structure of VIGGDECDIN EHPFLAFMYY SPRYFCGMTL INQEWVLTAA HCRYFCGMTL IHLGVHRESE
KANYDEVRRF PKEKYFIFCD NNFTDDEVDK DIMLIRLDKP VSNSEHIAPL SLPSNPPSVG SVCRIMGWGQ TTTSPIDVLS PDEPHCANIN LFDNTVCHTA HPQVANTRTS TDTLCAGDLQ
GGRDTCNGDS GGPLICNEQL HGILSWGGDP CAQPNKPAFY TKVYYFDHPW IKSIIAGNKK TVNFTCPPLR SDAKDDSTTY INQEWDWVLT AEHCDRTHMR NSFYDYSSIN SDS.
Titration experiments did not show the presence of free sulfhydryl groups after 4 h incubation, nor were differences found
in relation to titration kinetics in the presence of nondenaturating buffer. The isolation of this protein, Ba III-4, is of
potential interest for the understanding of the pathomechanism of the snake venom action and for the identification of new
blood coagulation enzymes of natural sources. 相似文献
110.