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121.
122.
Kamynina E Kauppinen K Duan F Muakkassa N Manor D 《Molecular and cellular biology》2007,27(5):1809-1822
The dbl proto-oncogene product is a prototype of a growing family of guanine nucleotide exchange factors (GEFs) that stimulate the activation of small GTP-binding proteins from the Rho family. Mutations that result in the loss of proto-Dbl's amino terminus produce a variant with constitutive GEF activity and high oncogenic potential. Here, we show that proto-Dbl is a short-lived protein that is kept at low levels in cells by efficient ubiquitination and degradation. The cellular fate of proto-Dbl is regulated by interactions with the chaperones Hsc70 and Hsp90 and the protein-ubiquitin ligase CHIP, and these interactions are mediated by the spectrin domain of proto-Dbl. We show that CHIP is the E3 ligase responsible for ubiquitination and proteasomal degradation of proto-Dbl, while Hsp90 functions to stabilize the protein. Onco-Dbl, lacking the spectrin homology domain, cannot bind these regulators and therefore accumulates in cells at high levels, leading to persistent stimulation of its downstream signaling pathways. 相似文献
123.
Repanas K Zingler N Layer LE Schumann GG Perrakis A Weichenrieder O 《Nucleic acids research》2007,35(14):4914-4926
The human LINE-1 endonuclease (L1-EN) is the targeting endonuclease encoded by the human LINE-1 (L1) retrotransposon. L1-EN guides the genomic integration of new L1 and Alu elements that presently account for ~28% of the human genome. L1-EN bears considerable technological interest, because its target selectivity may ultimately be engineered to allow the site-specific integration of DNA into defined genomic locations. Based on the crystal structure, we generated L1-EN mutants to analyze and manipulate DNA target site recognition. Crystal structures and their dynamic and functional analysis show entire loop grafts to be feasible, resulting in altered specificity, while individual point mutations do not change the nicking pattern of L1-EN. Structural parameters of the DNA target seem more important for recognition than the nucleotide sequence, and nicking profiles on DNA oligonucleotides in vitro are less well defined than the respective integration site consensus in vivo. This suggests that additional factors other than the DNA nicking specificity of L1-EN contribute to the targeted integration of non-LTR retrotransposons. 相似文献
124.
Szotkowski T Szotkowska R Pikalova Z Tichy T Flodr P Tichy M Houserkova D Benysek V Zlamalova N Ruzicka V Indrak K 《Biomedical papers of the Medical Faculty of the University Palacky, Olomouc, Czechoslovakia》2007,151(1):113-116
BACKGROUND: Spontaneous splenic rupture (SSR) is a very rare complication described in several hundred patients, mainly as case reports. It is defined as a splenic rupture without antecedent injury. The authors of the present paper describe the only two SSR cases diagnosed at the Hemato-oncology department, coincidentally in one year. PATIENTS: The first patient was admitted to hospital because of planned chemotherapy for relapsed hairy cell leukemia. The second was directed to the Hemato-oncology outpatient department because of anemia and painful splenomegaly diagnosed by a physician. The diagnose of hematologic malignancy (diffuse large B-cell lymphoma) was determined subsequently on the basis of histological examination of the spleen. CONCLUSION: It is necessary to consider SSR not only in patients with known diagnosis of malignant disease but in the patients with negative anamnesis, too. The aim of the paper is to draw attention to the existence of this complication. 相似文献
125.
Engineered protein libraries, defined here as a collection of different mutant variants of a single specific protein, are intentionally designed to be rich in molecular diversity and can span ranges from as little as 400 different variants to greater than 10(12) members per library. The goal of engineering libraries is to generate new protein variants, identified upon screening, that possess desired novel properties. Exploitation of the natural organization of the genetic code has led to 'focused' libraries that are lower in overall complexity yet biased towards variants with preferred biophysical properties. An emerging trend, in which computational algorithms are blended with in vivo screens, is also leading towards greater and more rapid success in the field of protein design. 相似文献
126.
Ausmees N Wahlstedt H Bagchi S Elliot MA Buttner MJ Flärdh K 《Molecular microbiology》2007,65(6):1458-1473
Sporulation in aerial hyphae of Streptomyces coelicolor involves profound changes in regulation of fundamental morphogenetic and cell cycle processes to convert the filamentous and multinucleoid cells to small unigenomic spores. Here, a novel sporulation locus consisting of smeA (encoding a small putative membrane protein) and sffA (encoding a SpoIIIE/FtsK-family protein) is characterized. Deletion of smeA-sffA gave rise to pleiotropic effects on spore maturation, and influenced the segregation of chromosomes and placement of septa during sporulation. Both smeA and sffA were expressed specifically in apical cells of sporogenic aerial hyphae simultaneously with or slightly after Z-ring assembly. The presence of smeA-like genes in streptomycete chromosomes, plasmids and transposons, often paired with a gene for a SpoIIIE/FtsK- or Tra-like protein, indicates that SmeA and SffA functions might be related to DNA transfer. During spore development SffA accumulated specifically at sporulation septa where it colocalized with FtsK. However, sffA did not show redundancy with ftsK, and SffA function appeared distinct from the DNA translocase activity displayed by FtsK during closure of sporulation septa. The septal localization of SffA was dependent on SmeA, suggesting that SmeA may act as an assembly factor for SffA and possibly other proteins required during spore maturation. 相似文献
127.
128.
Zhao T Zhou X Szabó N Leitges M Alvarez-Bolado G 《Genesis (New York, N.Y. : 2000)》2007,45(12):781-787
We have knocked-in Cre-IRES-EGFP in the Foxb1 locus by homologous recombination in embryonic stem cells. We removed the PGK-neo cassette (which was flanked by FRT sequences) by crossing with the FLPeR deleter mouse. The Foxb1(Cre) line showed Cre recombinase activity as well as EGFP fluorescence reproducing Foxb1 expression accurately. By crossing Foxb1(Cre) mice with the ROSA26R and Z/AP mouse reporter lines we have been able to trace the lineage of Foxb1-expressing cells. Early transient expression of Foxb1 in the paraxial mesoderm translates into labeling of the somites. In the central nervous system (CNS), the Foxb1 lineage includes the thalamus and mammillary body (hypothalamus), brainstem, and the ventral spinal cord and floor plate. 相似文献
129.
Álvaro Rodríguez-Peña Ana C. Gonzalez-Franco Jared Hernández-Huerta Nora A. Salas-Salazar Dámaris L. Ojeda-Barrios Esteban Sánchez Loreto Robles-Hernández 《Phyton》2022,91(7):1341-1351
Antibiotics are widely used in fire blight management programs, yet there are no studies that demonstrate the evaluation of their efficacy in Mexico. Therefore, the present study was conducted to investigate the effects of the active ingredients in five commercial products (Kasumin® 2L, Agrygent Plus®, Agricultural Terramycin®, Agrimicin® 100, and Actigard®) on fire blight suppression, and fruit yield and quality of apple (Malus domestica Borkh.) cv. Golden Glory. The experiment was conducted in a commercial orchard using a completely randomized block design, with six treatments: (1) Oxytetracycline [Ox], 110 mg L−1; (2) Kasugamycin [Kas], 4.7 mL L−1; (3) Oxytetracycline + Gentamicin [Ox + Gen], 48 mg L−1 + 12 mg L−1; (4) Streptomycin + Oxytetracycline [Str + Ox], 90 mg L−1 + 9 mg L−1; (5) Acibenzolar-S-methyl [ASM], 70 mg L−1; and (6) Control, only water, with four replications, and three 11-year-old trees as an experimental unit. Variables of infection including flowers, shoots and fruits, yield and fruit quality were evaluated. All treatments suppressed infection in flowers, shoots, and fruits. ASM provided the highest levels of reduction of flower and shoot infection, while Kas had the least effect on the reduction of infection in these variables. The Ox + Gen treatment had the greatest suppression of fruit infection, and the best results on fruit yield and quality, followed by Ox and ASM. This is the first study conducted to evaluate the efficacy of the active ingredients of five commercial products used for the management of fire blight in apple trees in Mexico. 相似文献
130.
Brandstaetter Christian Fricko Nora Rahimi Mohammad J. Fellner Johann Ecker-Lala Wolfgang Druzhinina Irina S. 《Biodegradation》2022,33(1):71-85
Biodegradation - Biological waste degradation is the main driving factor for landfill emissions. In a 2-year laboratory experiment simulating different landfill in-situ aeration scenarios, the... 相似文献