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51.
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Tanit Guitart Daria Picchioni David Pi?eyro Lluís Ribas de Pouplana 《Nucleic acids research》2013,41(13):6595-6608
The translation of genes encoded in the mitochondrial genome requires specific machinery that functions in the organelle. Among the many mutations linked to human disease that affect mitochondrial translation, several are localized to nuclear genes coding for mitochondrial aminoacyl-transfer RNA synthetases. The molecular significance of these mutations is poorly understood, but it is expected to be similar to that of the mutations affecting mitochondrial transfer RNAs. To better understand the molecular features of diseases caused by these mutations, and to improve their diagnosis and therapeutics, we have constructed a Drosophila melanogaster model disrupting the mitochondrial seryl-tRNA synthetase by RNA interference. At the molecular level, the knockdown generates a reduction in transfer RNA serylation, which correlates with the severity of the phenotype observed. The silencing compromises viability, longevity, motility and tissue development. At the cellular level, the knockdown alters mitochondrial morphology, biogenesis and function, and induces lactic acidosis and reactive oxygen species accumulation. We report that administration of antioxidant compounds has a palliative effect of some of these phenotypes. In conclusion, the fly model generated in this work reproduces typical characteristics of pathologies caused by mutations in the mitochondrial aminoacylation system, and can be useful to assess therapeutic approaches. 相似文献
53.
Jan Piťha 《Cell and tissue research》1968,90(4):563-569
Summary Paneth cells of rabbit small intestine almost constantly contain inclusions of variable size which consist of two components. The first consists of cylindrical bodies formed by concentric or spiral dense lamellae. The second is formed by tubules with triple-layered walls which may be arranged in a hexagonal pattern. The density of arrangement of both components is variable. The structure of inclusions is discussed in relation to their composition and derivation and lipid or lipoprotein composition is assumed. 相似文献
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Meizhi Xu Xu Gu Nengsong Liang Xinxin Bian Hong Wang Yaxin Qin Limin Pi Shuang Wu 《植物学报(英文版)》2020,62(7):897-911
Root stem cell niche (SCN) consists of a quiescent center (QC) and surrounding stem cells. Disrupted symplastic communication leads to loss of stemness in the whole SCN. Several SCN regulators were reported to move between cells for SCN maintenance. However, single mutant of these regulators is insufficient to abolish QC stemness despite the high differentiation rate in surrounding stem cells. To dissect the mechanism behind such distinct stemness in SCN, we combined the mis‐expression strategy with pWOX5:icals3m system in which QC is symplastically isolated. We found the starch accumulation in QC could be synergistically repressed by WUSCHEL‐RELATED HOMEOBOX 5 (WOX5), SHORT‐ROOT (SHR), SCARCROW (SCR), and PLETHORA (PLT). Like PLTs, other core regulators also exhibited dimorphic functions by inhibiting differentiation at a higher dose while promoting cell division at a low protein level. Being located in the center of the intersected expression zones, QC cells receive the highest level of core regulators, forming the most robust stemness within SCN. WUSCHEL‐RELATED HOMEOBOX 5 was sufficient to activate PLT1/2 expression, contributing to the QC‐enriched PLTs. Our results provide experimental evidence supporting the long‐standing hypothesis that the combination of spatial expression, synergistic function and dosage effect of core regulators result in spatially distinct stemness in SCN. 相似文献
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Cora E. Lewis John P. Bantle Alain G. Bertoni George Blackburn Frederick L. Brancati George A. Bray Lawrence J. Cheskin Jeffrey M. Curtis Caitlin Egan Mary Evans John P. Foreyt Siran Ghazarian Bethany Barone Gibbs Stephen P. Glasser Edward W. Gregg Helen P. Hazuda Louise Hesson James O. Hill Edward S. Horton Van S. Hubbard John M. Jakicic Robert W. Jeffery Karen C. Johnson Steven E. Kahn Abbas E. Kitabchi Dalane Kitzman William C. Knowler Edward Lipkin Sara Michaels Maria G. Montez David M. Nathan Ebenezer Nyenwe Jennifer Patricio Anne Peters Xavier Pi‐Sunyer Henry Pownall David M. Reboussin Donna H. Ryan Thomas A. Wadden Lynne E. Wagenknecht Holly Wyatt Rena R. Wing Susan Z. Yanovski 《Obesity (Silver Spring, Md.)》2020,28(2):247-258
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Ariana M. Chao Thomas A. Wadden Robert I. Berkowitz George Blackburn Paula Bolin Jeanne M. Clark Mace Coday Jeffrey M. Curtis Linda M. Delahanty Gareth R. Dutton Mary Evans Linda J. Ewing John P. Foreyt Linda J. Gay Edward W. Gregg Helen P. Hazuda James O. Hill Edward S. Horton Denise K. Houston John M. Jakicic Robert W. Jeffery Karen C. Johnson Steven E. Kahn William C. Knowler Anne Kure Katherine L. Michalski Maria G. Montez Rebecca H. Neiberg Jennifer Patricio Anne Peters Xavier Pi‐Sunyer Henry Pownall David Reboussin Bruce Redmon W. Jack Rejeski Helmut Steinburg Martha Walker Donald A. Williamson Rena R. Wing Holly Wyatt Susan Z. Yanovski Ping Zhang 《Obesity (Silver Spring, Md.)》2020,28(5):893-901
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Li‐Hsuan Ho Yung‐I Lee Shu‐Ying Hsieh I‐Shiuan Lin Yun‐Chien Wu Han‐Yu Ko Patrick A. Klemens H. Ekkehard Neuhaus Yi‐Min Chen Tzu‐Pi Huang Chih‐Hsin Yeh Woei‐Jiun Guo 《Plant, cell & environment》2021,44(1):20-33
Gastrodia elata, a fully mycoheterotrophic orchid without photosynthetic ability, only grows symbiotically with the fungus Armillaria. The mechanism of carbon distribution in this mycoheterotrophy is unknown. We detected high sucrose concentrations in all stages of Gastrodia tubers, suggesting sucrose may be the major sugar transported between fungus and orchid. Thick symplasm‐isolated wall interfaces in colonized and adjacent large cells implied involvement of sucrose importers. Two sucrose transporter (SUT)‐like genes, GeSUT4 and GeSUT3, were identified that were highly expressed in young Armillaria‐colonized tubers. Yeast complementation and isotope tracer experiments confirmed that GeSUT4 functioned as a high‐affinity sucrose‐specific proton‐dependent importer. Plasma‐membrane/tonoplast localization of GeSUT4‐GFP fusions and high RNA expression of GeSUT4 in symbiotic and large cells indicated that GeSUT4 likely functions in active sucrose transport for intercellular allocation and intracellular homeostasis. Transgenic Arabidopsis overexpressing GeSUT4 had larger leaves but were sensitive to excess sucrose and roots were colonized with fewer mutualistic Bacillus, supporting the role of GeSUT4 in regulating sugar allocation. This is not only the first documented carbon import system in a mycoheterotrophic interaction but also highlights the evolutionary importance of sucrose transporters for regulation of carbon flow in all types of plant‐microbe interactions. 相似文献