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71.
Mutant tobacco mosaic virus (TMV) coat proteins (CPs) with known amino acid replacements provide well defined examples of destabilized tertiary structures. Here we show that misfolded TMV CPs, but not functional wild-type CPs, induce massive ubiquitylation in tobacco cells and that denatured, insoluble CP subunits are the main substrates of ubiquitin conjugation. As TMV CPs can be easily manipulated they are unique tools to study the molecular basis of the plant cell's response to aberrant protein structures and the associated intracellular stress reactions. 相似文献
72.
Plant genome archaeology: evidence for conserved ancestral chromosome segments in dicotyledonous plant species 总被引:3,自引:0,他引:3
Dominguez I Graziano E Gebhardt C Barakat A Berry S Arús P Delseny M Barnes S 《Plant biotechnology journal》2003,1(2):91-99
We have developed genetic maps, based on expressed sequence tags (ESTs) that are homologous to Arabidopsis genes, in four dicotyledonous crop plant species from different families. A comparison of these maps with the physical map of Arabidopsis reveals common genome segments that appear to have been conserved throughout the evolution of the dicots. In the four crop species analysed these segments comprise between 16 and 33% of the Arabidopsis genome. Our findings extend the synteny patterns previously observed only within plant families, and indicate that structural and functional information from the model species will be, at least in part, applicable in crop plants with large genomes. 相似文献
73.
74.
Expression of Measles Virus V Protein Is Associated with Pathogenicity and Control of Viral RNA Synthesis 总被引:1,自引:6,他引:1 下载免费PDF全文
Christiane Tober Marion Seufert Henriette Schneider Martin A. Billeter Ian C. D. Johnston Stefan Niewiesk Volker ter Meulen Sibylle Schneider-Schaulies 《Journal of virology》1998,72(10):8124-8132
Nonstructural proteins encoded by measles virus (MV) include the V protein which is translated from an edited P mRNA. V protein is not associated with intracellular or released viral particles and has recently been found to be dispensable for MV propagation in cell culture (H. Schneider, K. Kaelin, and M. A. Billeter, Virology 227:314–322, 1997). Using recombinant MVs (strain Edmonston [ED]) genetically engineered to overexpress V protein (ED-V+) or to be deficient for V protein (ED-V−), we found that in the absence of V both MV-specific proteins and RNAs accumulated to levels higher than those in the parental MV molecular clone (ED-tag), whereas MV-specific gene expression was strongly attenuated in human U-87 glioblastomas cells after infection with ED-V+. The titers of virus released from these cells 48 h after infection with either V mutant virus were lower than those from cells infected with ED-tag. Similarly, significantly reduced titers of infectious virus were reisolated from lung tissue of cotton rats (Sigmodon hispidus) after intranasal infection with both editing mutants compared to titers isolated from ED-tag-infected animals. In cell culture, expression of V protein led to a redistribution of MV N protein in doubly transfected Cos-7 cells, indicating that these proteins form heterologous complexes. This interaction was further confirmed by using a two-hybrid approach with both proteins expressed as Gal4 or VP16 fusion products. Moreover, V protein efficiently competed complexes formed between MV N and P proteins. These findings indicate that V protein acts to balance accumulation of viral gene products in cell culture, and this may be dependent on its interaction with MV N protein. Furthermore, expression of V protein may contribute to viral pathogenicity in vivo. 相似文献
75.
Bogdan Flis Jacek Hennig Danuta Strzelczyk-yta Christiane Gebhardt Waldemar Marczewski 《Molecular breeding : new strategies in plant improvement》2005,15(1):95-101
A novel locus for extreme resistance to Potato virus Y (PVY), Ry-fsto, was identified on potato chromosome XII. The gene Ry-fsto has been introgressed from the wild potato species Solanum stoloniferum. Inheritance of Ry-fsto in the tetraploid potato population Rysto was consistent with the model of a single, dominant gene. Bulked segregant analysis identified an ISSR (inter-simple sequence repeat) marker UBC 857980 linked to Ry-fsto. This marker mapped to linkage group XII of a reference potato RFLP (restriction fragment length polymorphism) map. Chromosome XII specific RFLP markers were converted into PCR-based STS and CAPS markers and tested for linkage with Ry-fsto in the population Rysto. CAPS marker GP122718 was tightly linked to the resistance gene and was successfully used to identify Polish and German cultivars expressing extreme resistance to PVY. This indicates that the source of Ry-fsto has been widely utilized in various potato breeding programs and can be monitored by a diagnostic marker in marker-assisted selection. 相似文献
76.
Alexis Jourdain Mariusz Karbowski Yves Mattenberger Sébastien Herzig Pascaline Clerc Ines Raschke Carsten Merkwirth Sarah Ehses Frank Krause David C Chan Christiane Alexander Christoph Bauer Richard Youle Thomas Langer Jean‐Claude Martinou 《The EMBO journal》2009,28(11):1589-1600
Mitochondria are dynamic organelles, the morphology of which results from an equilibrium between two opposing processes, fusion and fission. Mitochondrial fusion relies on dynamin‐related GTPases, the mitofusins (MFN1 and 2) in the outer mitochondrial membrane and OPA1 (optic atrophy 1) in the inner mitochondrial membrane. Apart from a role in the maintenance of mitochondrial DNA, little is known about the physiological role of mitochondrial fusion. Here we report that mitochondria hyperfuse and form a highly interconnected network in cells exposed to selective stresses. This process precedes mitochondrial fission when it is triggered by apoptotic stimuli such as UV irradiation or actinomycin D. Stress‐induced mitochondrial hyperfusion (SIMH) is independent of MFN2, BAX/BAK, and prohibitins, but requires L‐OPA1, MFN1, and the mitochondrial inner membrane protein SLP‐2. In the absence of SLP‐2, L‐OPA1 is lost and SIMH is prevented. SIMH is accompanied by increased mitochondrial ATP production and represents a novel adaptive pro‐survival response against stress. 相似文献
77.
78.
The nucleotide sequence data reported in this paper have been submitted to the GenBank nucleotide sequence data base and have been assigned the accesion number M74842. The name DQB1*0304 has been officially assigned by the WHO Nomenclature Committee in November 1991. This follows the agreed policy that, subject to the conditions stated in the most recent Nomenclature Report (WHO Nomenclature Committee for factors of the HLA system, 1991), names will be assigned to new sequences as they are identified. List of such new names will be published in the following WHO Nomenclature Report. 相似文献
79.
Binding of ribosomes to the 5' leader sequence (N = 258) of RNA 3 from alfalfa mosaic virus. 总被引:2,自引:8,他引:2 下载免费PDF全文
RNA 3 of alfalfa mosaic virus (AlMV) contains information for two genes: near the 5' end an active gene coding for a 35 Kd protein and, near the 3' end, a silent gene coding for viral coat protein. We have determined a sequence of 318 nucleotides which contains the potential initiation codon for the 35 Kd protein at 258 nucleotides from the 5' end. This long leader sequence can form initiation complexes containing three 80 S ribosomes. A shorter species of RNA, corresponding to a molecule of RNA 3 lacking the cap and the first 154 nucleotides (RNA 3') has been isolated. The remaining leader sequence of 104 nucleotides in RNA 3' forms a single 80 S initiation complex with wheat germ ribosomes. The location of the regions of the leader sequence of RNA 3 involved in initiation complex formation with 80 S ribosomes is reported. 相似文献
80.
Matrix fibronectin binds gammaretrovirus and assists in entry: new light on viral infections 总被引:1,自引:0,他引:1 下载免费PDF全文
A major entry route for the gammaretrovirus amphotropic murine leukemia virus (A-MLV) into NIH 3T3 fibroblasts is via caveola-dependent endocytosis. However, during the infection time, few viral particles can be observed intracellularly. Analyzing the dynamics of the A-MLV infection process by using total internal reflection fluorescence microscopy, we show that the majority of viruses are extracellular and bound to the fibronectin matrix. Moreover, the amounts of bound virus and of fibronectin correlated. Using confocal microscopy, nanoparticles targeted to fibronectin by a III1C-fibronectin fragment or anti-fibronectin antibody were detected intracellularly in NIH 3T3 cells; unconjugated nanoparticles neither bound to cells nor were detectable intracellularly. Furthermore, A-MLV colocalized intracellularly with the fibronectin-targeted nanoparticles, suggesting that they were taken up by the same cellular pathway. Both A-MLV entry and fibronectin turnover depend on caveolar endocytosis, and we found that inhibiting viral binding to the extracellular NIH 3T3 fibronectin-matrix dramatically reduced A-MLV infection, indeed, showing an active role of fibronectin in infection. We suggest that binding to the cellular fibronectin matrix provides a new mechanism by which viruses can enter cells. 相似文献