956 resultados para Site of memory


Relevância:

100.00% 100.00%

Publicador:

Resumo:

The DNA-activated serine/threonine protein kinase (DNA-PK) is composed of a large (approximately 460 kDa) catalytic polypeptide (DNA-PKcs) and Ku, a heterodimeric DNA-binding component (p70/p80) that targets DNA-PKcs to DNA. A 41-kbp segment of the DNA-PKcs gene was isolated, and a 7902-bp segment was sequenced. The sequence contains a polymorphic Pvu II restriction enzyme site, and comparing the sequence with that of the cDNA revealed the positions of nine exons. The DNA-PKcs gene was mapped to band q11 of chromosome 8 by in situ hybridization. This location is coincident with that of XRCC7, the gene that complements the DNA double-strand break repair and V(D)J recombination defects (where V is variable, D is diversity, and J is joining) of hamster V3 and murine severe combined immunodeficient (scid) cells.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Ear3/COUP is an orphan member of the steroid/thyroid hormone receptor superfamily of transcription factors and binds most tightly to a direct repeat of AGGTCA with 1 nucleotide in between (DR1). Ear3/COUP also binds with a similar affinity to the palindromic thyroid hormone response element (TRE). This binding preference of Ear3/COUP is same as that of the retinoid X receptor (RXR), which is another member of the superfamily. In the present study, we identified a sequence responsible for Ear3/COUP-mediated transactivation in the region downstream of the transcription start site of the mouse mammary tumor virus promoter. This cis-acting sequence was unresponsive to RXR. When the DR1 or TRE sequence was added upstream of the promoter, transactivation by Ear3/COUP was completely abolished, whereas RXR enhanced transcription from the promoter. The mode of action of Ear3/COUP could be utilized to control complex gene expressions in morphogenesis, homeostasis, and development.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

We have explored the feasibility of using a "double-tagging" assay for assessing which amino acids of a protein are responsible for its binding to another protein. We have chosen the adenovirus E1A-retinoblastoma gene product (pRB) proteins for a model system, and we focused on the high-affinity conserved region 2 of adenovirus E1A (CR2). We used site-specific mutagenesis to generate a mutant E1A gene with a lysine instead of an aspartic acid at position 121 within the CR2 site. We demonstrated that this mutant exhibited little binding to pRB by the double-tagging assay. We also have shown that this lack of binding is not due to any significant decrease in the level of expression of the beta-galactosidase-E1A fusion protein. We then created a "library" of phage expressing beta-galactosidase-E1A fusion proteins with a variety of different mutations within CR2. This library of E1A mutations was used in a double-tagging screening to identify mutant clones that bound to pRB. Three classes of phage were identified: the vast majority of clones were negative and exhibited no binding to pRB. Approximately 1 in 10,000 bound to pRB but not to E1A ("true positives"). A variable number of clones appeared to bind equally well to both pRB and E1A ("false positives"). The DNA sequence of 10 true positive clones yielded the following consensus sequence: DLTCXEX, where X = any amino acid. The recovery of positive clones with only one of several allowed amino acids at each position suggests that most, if not all, of the conserved residues play an important role in binding to pRB. On the other hand, the DNA sequence of the negative clones appeared random. These results are consistent with those obtained from other sources. These data suggest that a double-tagging assay can be employed for determining which amino acids of a protein are important for specifying its interaction with another protein if the complex forms within bacteria. This assay is rapid and up to 1 x 10(6) mutations can be screened at one time.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Important changes have occurred in recent years in the attitude of a majority of the German elite towards the history of the 20th century and the political identity built on collective memory. Until recently, the sense of guilt for the crimes of the Third Reich and the obligation to remember were prevalent. While these two elements of Germany's memory of World War II are still important, currently the focus increasingly shifts to the German resistance against Nazism and the fate of the Germans who suffered in the war. Positive references to Germany's post-war history also occupy more and more space in the German memory. In 2009, i.e. the year of the 60th anniversary of the Federal Republic of Germany and the 20th anniversary of the fall of Communism, the efforts of German public institutions concentrate on promoting a new canon of history built around the successful democratisation and Germany's post-war economic success. The purpose behind these measures is to build a common historical memory that could be shared by the eastern and western parts of Germany and appeal to Germany's immigrants, who account for a growing proportion of the society.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Mycoplasma bovis is a highly contagious bacterium, which predominantly causes chronic pneumonia, otitis and arthritis in calves and mastitis in adult cattle. In humans, Mycoplasma species have been associated with post-surgical infections. The present study aimed to identify the bacteria associated with three outbreaks of infected seromas after caesarian section in Belgian Blue beef cattle. A total of 10 cases occurred in three herds which were in close proximity of each other and shared the same veterinary practice. M. bovis could be cultured from seroma fluid in five of the six referred animals, mostly in pure culture and was isolated from multiple chronic sites of infection (arthritis and mastitis) as well. DNA fingerprinting of the isolates targeting two insertion sequence elements suggested spread of M. bovis from chronic sites of infection (udder and joints) to the postsurgical seromas. Identical genetic profiles were demonstrated in two animals from two separate farms, suggesting spread between farms. Mortality rate in the referred animals positive for M. bovis in a seroma was 80% (4/5), despite intensive treatment. A massive increase in antimicrobial use was observed in every affected farm. These observations demonstrate involvement of mycoplasmas in outbreaks of postsurgical seromas in cattle.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Radiocarbon ages on CaCO3 from deep-sea cores offer constraints on the nature of the CaCO3 dissolution process. The idea is that the toll taken by dissolution on grains within the core top bioturbation zone should be in proportion to their time of residence in this zone. If so, dissolution would shift the mass distribution in favor of younger grains, thereby reducing the mean radiocarbon age for the grain ensemble. We have searched in vain for evidence supporting the existence of such an age reduction. Instead, we find that for water depths of more than 4 km in the tropical Pacific the radiocarbon age increases with the extent of dissolution. We can find no satisfactory steady state explanation and are forced to conclude that this increase must be the result of chemical erosion. The idea is that during the Holocene the rate of dissolution of CaCO3 has exceeded the rain rate of CaCO3. In this circumstance, bioturbation exhumes CaCO3 from the underlying glacial sediment and mixes it with CaCO3 raining from the sea surface.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Dedicated to Christopher Morley. Dedication: p. v-xxx.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Bibliography: p. 47-65.