The Effect of Amyloid Prions and Second-Site Suppressor Mutations - Term Paper Example

HЕ ЕFFЕСT ОF АMYLОID РRIОNS АND SЕСОND-SITЕ SUРРRЕSSОR MUTАTIОNS TО THЕ GRОWTH DЕFЕСTS ОF VRР1 MUTАNT YЕАST СЕLLS Name University Date Discussion The vpr 1 mutant cells demonstrate varied characteristics and traits. The fact that these mutant cells show different characteristics in different environments, it is observable in experimental procedures that different phenotypes exist. In the various experimental conditions, vpr 1 cells behave uniquely. This reveals that the vpr 1 mutant cells are capable of assuming different phenotypic character traits. In each given medium, the mutant cells are likely to show varied responses to the prevailing environment. Based on this observation, it is important that researchers understand the underlying impacts the different adaptive mechanisms have on the ultimate phenotypic trait of the vpr 1 cells. In order to understand and adequately explore the links between the amyloid prions and actin assembly proteins, it is imperative that the different phenotypes of the vpr 1 mutant cells are exemplified and exhaustively examined. In this study, the observed mutant cells have demonstrated sensitivity to various situations. The notable traits include sensitivity to different temperature variations among others. Ganusova, Ozollins, Bhagat and Newman (2006, pp 625) observes that alterations in the medium used in culturing have significant effects on the growth of different strains of the vpr 1 mutant genes. In effect, it is apparent that the phenotypic characteristics of these genes are influenced by not only the medium but also on the adaptive mechanisms that determine the propagation of new generations. The first notable phenotypic character trait is that vpr 1 mutant cells are temperature sensitive. This sensitivity is, on the other hand attributable to a number of facts. For instance, the mutant cells have been observed to behave in a manner that demonstrates resistance to temperature changes. Whereas curing samples of the mutant cells using GuHCl-treatment does not indicate significant influence on the growth at certain temperatures, the experimental results revealed that at 37oC culture, there were no observable impacts. As a matter of fact, the temperature changes did not even boost or hasten the appearance of impulsive temperature-resistant colonies even after the culture was changed. According to research, temperature sensitive mutant genes are observable in different cultures. This is because the GuHCl, is denaturing agent and thus affects the growth of the prion cells in yeast cultures (Tuite and Mundy 1981, pp 694). The effects of GuHCl on growth o different ultures are diverse. The characterization of these mutant genes is varied and some colonies do not behave in similar manners. In this observation, the underlying fact is that successive mutations and spontaneous generations cultured in temperatures above 37 degrees and above give varied results. Most importantly, the different mutant colonies demonstrate different reactions to temperature changes. In this study, the AMY89 vrp1Δ mutants #1 showed significant growth at 24oC. Additionally, the AMY89 vrp1Δ mutant #2 reported similar results. This exemplifies the fact that the mutants behave differently when exposed to various temperature conditions. This is an indication of the variation in temperature sensitivity in the vpr 1mutant cells. It is imperative to note that following the changes in the nature of the culture, the study identified that the numerous strains of the vpr 1 mutant cells are apt to demonstrate different sensitivity levels and react to the changes according to the desired outcome the organism intends to effect. Cell morphology and aggregation are instrumental in the classification and analysis of organisms. This constitutes the observable features that an organism has when examined under a microscope. In this investigation, the researchers noted that a number of the vpr 1 mutant cells demonstrated abnormal morphologies in varied manners. For instance, the number of unbudded and budded cells in each culture was different. However, the size of the buds was also identified as a different morphological difference. This was identified during the cell division stages. It should be noted that the temperature of the culture has direct impacts on the growth of the buds as noted in the experimental results obtained using different categories of the vpr 1 mutant cells. Whereas measures of significance do not indicate that differences in morphologies are evident in the experiments performed, it is observable that there are notable differences in the morphologies of the subject mutant cells. The statistical analysis as presented in table six shows that difference in the percentages of cells in different cell cycle stages including normal and abnormal morphologies between AMY88vrp1ΔGuHCl- treated and mock-treated apparent, on the contrary, this has no significant values. Ganusova (2006, 23) points out that inherent genotype differences lead to the gross defects in the not only mating but also mating and the overall morphology of the studied strains of the vpr 1 mutant genes. Based on the findings of the study, it is apparent that the differences in morphology are a result of the unidentified relationship between the factors that influence the developments in cell division. It is notable that the expectations of the research were to explore the impacts of the changes in the morphological aspects of the mutant cells. This research failed to show the significance levels of the question on the impacts of morphology on the mutant cells under study. At 24OC for AMY88 (vrp1Δ) and AMY89 (vrp1Δ), there is thick growth recorded. However, there was very little and growth at 37oC. The study hypothesized that the formation of prions of the vrp1Δ phenotype is influenced by temperature changes and sensitivity to salt variations. On analysis if the data collected, it is apparent that the rate of formation of these cells is influenced by the temperature and the culture medium. This is illustrated by the fact that the growth of colonies in GuHCL cultured mediums demonstrated slow growth responses in temperatures above 240C. Additionally, cells cultured in 370C environments are adversely affected. Sensitivity to salts and other saline environments is often observable in many organisms. In conducting the experiment, the researchers observed that it was important to analyse the impacts of different salt concentrations and how the concentrations influenced growth of the mutant cells. The various concentrations of salts have direct impacts on the growth of the vpr 1 mutant cells. Scholarly articles present a number of data on the reactions of various strains of the gene. For example, previous studies have shown that salt concentrations directly influence the growth of a number of yeast strains. Interestingly the salt concentrations depend on the temperature of the medium in which the strains are cultured. In this investigation, the researchers identified that significant relationship. In essence, introducing plasmids that encode fragments of Vrp1p into vrp1cells especially AMY88 in some cases restore both temperature-resistance and salt-resistance (Ross, Baxa and Wickner 2004, 7209). However, plasmids expressing other Vrp1p fragments restore only temperature-resistance. The action of these cells is also considered d as the determining factors of spontaneous growth. In line with the revelations that the study has revealed, it is notable that the mutant cells adopt a different and unique behaviour when placed in different environments. Nonetheless, this is informed by the mutant cells environment and the effects of the resistance to the various conditions. A comparative analysis of mutant cells reaction to temperature and salt demonstrates that the formation of vpr 1 is influenced by a number of factors that are considerably in harmony with the environment in which the organism is placed. In essence, it is observable that various strains of vpr 1 are sensitive to temperature in varied ways. From the results of this study, temperature sensitive phenotypes are identifiable. Apart from this phenotypic difference, there are identifiable morphological differences that differentiate the vpr 1 mutant genes. Additionally, it is important to understand that different strains of the vpr 1 mutant genes are insensitive to salt levels. This is an indication of the disparities that define the mutation. Links between Amyloid prions and Actin assembly proteins The relationship between prions and the amyoid formatioin has been studied in the recent past. Research on the association between Amyloid prions and Actin assembly has been of fundamental concern to the modern day researchers. Most importantly, it has been observed that different links between the Actin assembly and Amyloid prions is accelerated by a host of other factors. Amongst these, the notable ones include the formation of the (PST-) chaperone Hsp 104p which supports the prion model. The model postulates that the inheritance of the PSI + is entirely based on the maintenance of the self propagating proteins. On the contrary, successive research has shown that this is not true in most cases. (Derkatch, Bradley, Zhou, Chernoff and Liebernman 1997, pp 510). Different studies have indicated that there are various changes and variations notable in studies on the relationship between Amyloid prions and Actin assembly proteins. The yeast prion is composed of Sup 35 protein that is transmitted to the offspring. Treatment of the SUP 35 samples using the guanidine hydrochloride enables researchers to analyse the diffusion properties using florescence methods. The analysis reveals the relationship between prions and the assembly proteins (Noma, Pack, Tsuji and Kinjo 2009, 1045). Prions have been associated with different disease in the recent research. This is attributable to various reasons. In recent research, the causative agents that major scholars and observers cite are either mammalian or yeast prions. Significant research findings point to this as a major factor. According to Saupe (2008, 234), the most extensively studied prions are yeast prions. These fall under the Ure2p. This is the protein involved in the regulation and use of the nitrogen. It is imperative to note that the Ure2p is equally involved in the normal functioning of the Sup35p protein. Consequently, the formation of this protein is adversely influenced by the presence of URE3 yeast prions. In cell division, the vpr1 cells play pivotal roles. The actin cytoskeleton in yeast cells comprises cortical actin patches and cytoplasmic actin cables that influence the genotypic and phenotypic character traits of the daughter cells. However, the daughter cells will ultimately have a phenotypic difference that is as a result of the environment in which the cell is placed. S As noted earlier, this is influenced by either the temperature or the salt content of the said medium or culture in which the organism is laced. In this study, it has been observed that the there are variations in both the phenotypic and phenotypic traits that various strains will take. Conversely, most of this is influenced by the environment and the heredity factors that influence the growth of the vpr 1 stable propagation. From the results obtained in the study, it is apparent that the transfer of GdnHCl-treated cells to GdnHCl-free medium turns around GdnHCl inhibition of [PSI+] seed duplication and permits the recreation of new prion seeds exponentially in the lack of ongoing protein synthesis. This causes the number of prion seeds to double every few minutes. However, in the lack of Hsp104, Sup35p aggregates become large but do not reproduce thus becoming diluted as the yeast divides. This is as noted in Tuite ete al(1981, pp695). List of References Derkatch, I, L., Bradley, E, M., Zhou, P., Chernoff, O, Y., Lieberman, S, W. 1997. Genetic and Environmental Factors Affecting the de novo Appearance of the [PST+] Prion in Saccharomyces cerevisae. Department of biological sciences. Illinois University. Noma, K, S., Pack, C., Tsuji, T., Kinjo, M., Taguchi, H. 2009. Single Mother-Daughter pair analysis to clarify the diffusion properties of yeast prion Sup35 guanidine-HCL-treated [PSI+] cells. Journal of Molecular Biology. 14(1045-1045) Ross, D, E., Baxa, U., Wickner, R, B. 2004. Scrambled Prion Domains Form Prions and Amyloid. Molecular and Cellular Biology. 24(16)7206-7216. Saupe, S, J. (2004). New Anti Prion Drugs Make Yeast Blush. Tuite, M, F. Mundy, C, R., Cox, B, S. 1981. Agents that cause a high frequency of genetic change from [psi+] to [psi-] in saccharomyces cerevisae. Botany School, South Parks Road, Oxford, U. K. Ganusova, E., Ozolins, N, L., Bhaghat, S., Newman, G., Wegryzyn, M., Chernoff, O.(2006). Modulation of PrioN Formation, Aggregation, and Toxicity by the Actin Cytoskeleton in Yeast. American Society for Microbiology. 26(2)618-627. Read More