Truncation of the Mrp20 Protein Reveals New Ribosome‐assembly Subcomplex in Mitochondria

Mitochondrial ribosomal protein 20 (Mrp20) is a component of the yeast mitochondrial large (54S) ribosomal subunit and is homologous to the bacterial L23 protein, located at the ribosomal tunnel exit site. The carboxy‐terminal mitochondrial‐specific domain of Mrp20 was found to have a crucial role in the assembly of the ribosomes. A new, membrane‐bound, ribosomal‐assembly subcomplex composed of known tunnel‐exit‐site proteins, an uncharacterized ribosomal protein, MrpL25, and the mitochondrial peroxiredoxin (Prx), Prx1, accumulates in an mrp20ΔC yeast mutant. Finally, data supporting the idea that the inner mitochondrial membrane acts as a platform for the ribosome assembly process are discussed

The Mitospecific Region of Mrp20 and its Importance for the Assembly of Mitochondrial Ribosomes in Saccharomyces cerevisiae

Yeast mitochondrial ribosomes are composed of an rRNA scaffold, encoded by the mitochondrial genome and many different proteins, which, with the exception of one, are encoded by nuclear genes. These ribosomal proteins are imported into the mitochondrial matrix following their synthesis in the cytosol, however, little is known about the subsequent events which result in an assembled, translationally-competent ribosome. Many of the mitochondrial ribosomal proteins bear homology to bacterial ancestors. In addition to the acquisition of mitochondrial targeting signals, a number of these nuclearly-encoded ribosomal proteins have acquired additional domains, often at their C-termini, which are termed mitochondrial-specific domains . The function(s) of these domains is currently unknown and it is postulated that they may be involved in the process of ribosomal assembly or for ensuring the targeting of the ribosome to the mitochondrial inner membrane where they are translationally-active. Mrp20 protein is a nuclearly-encoded component of the mitochondrial large ribosomal subunit and shares homology with bacterial ribosomal protein L23, a protein located at the exit site of the ribosomal polypeptide tunnel. Mrp20 contains a C-terminal mitochondrial-specific domain of unknown function. In this study, we demonstrate that the C-terminal mitochondrial-specific region of Mrp20 is important to support the assembly of active mitochondrial ribosomes. It is proposed that the proteins at the exit site such as Mrp20 and MrpL40 are important for the assembly of mitochondrial ribosomes. Furthermore, the data presented here indicates that in the absence of the C-terminal region of the Mrp20 protein, the process of assembly of the ribosome becomes stalled, and the accumulation of a novel ribosome intermediate complex is observed. The characterization of this novel intermediate, which furthers our understanding of the assembly process of ribosomes in mitochondria, is presented

A mixed method case study : Bar-On EQ-i framework of emotional intelligence and the school leadership experiences of principals who completed an urban leadership program in Northern California

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Mapping of the saccharomyces cerevisiae oxa1-mitochondrial ribosome interface and identification of MrpL40, a ribosomal protein in close proximity to oxal and critical for oxidative phosphorylation complex assembly

The Oxa1 protein plays a central role in facilitating the cotranslational insertion of the nascent polypeptide chains into the mitochondrial inner membrane. Mitochondrially encoded proteins are synthesized on matrix-localized ribosomes which are tethered to the inner membrane and in physical association with the Oxa1 protein. In the present study we used a chemical cross-linking approach to map the Saccharomyces cerevisiae Oxa1-ribosome interface, and we demonstrate here a close association of Oxa1 and the large ribosomal subunit protein, MrpL40. Evidence to indicate that a close physical and functional relationship exists between MrpL40 and another large ribosomal protein, the Mrp20/L23 protein, is also provided. MrpL40 shares sequence features with the bacterial ribosomal protein L24, which like Mrp20/L23 is known to be located adjacent to the ribosomal polypeptide exit site. We propose therefore that MrpL40 represents the Saccharomyces cerevisiae L24 homolog. MrpL40, like many mitochondrial ribosomal proteins, contains a C-terminal extension region that bears no similarity to the bacterial counterpart. We show that this C-terminal mitochondria-specific region is important for MrpL40's ability to support the synthesis of the correct complement of mitochondrially encoded proteins and their subsequent assembly into oxidative phosphorylation complexes

Mapping of the \u3cem\u3eSaccharomyces cerevisiae\u3c/em\u3e Oxa1-Mitochondrial Ribosome Interface and Identification of MrpL40, a Ribosomal Protein in Close Proximity to Oxa1 and Critical for Oxidative Phosphorylation Complex Assembly

The Oxa1 protein plays a central role in facilitating the cotranslational insertion of the nascent polypeptide chains into the mitochondrial inner membrane. Mitochondrially encoded proteins are synthesized on matrix-localized ribosomes which are tethered to the inner membrane and in physical association with the Oxa1 protein. In the present study we used a chemical cross-linking approach to map the Saccharomyces cerevisiae Oxa1-ribosome interface, and we demonstrate here a close association of Oxa1 and the large ribosomal subunit protein, MrpL40. Evidence to indicate that a close physical and functional relationship exists between MrpL40 and another large ribosomal protein, the Mrp20/L23 protein, is also provided. MrpL40 shares sequence features with the bacterial ribosomal protein L24, which like Mrp20/L23 is known to be located adjacent to the ribosomal polypeptide exit site. We propose therefore that MrpL40 represents the Saccharomyces cerevisiae L24 homolog. MrpL40, like many mitochondrial ribosomal proteins, contains a C-terminal extension region that bears no similarity to the bacterial counterpart. We show that this C-terminal mitochondria-specific region is important for MrpL40\u27s ability to support the synthesis of the correct complement of mitochondrially encoded proteins and their subsequent assembly into oxidative phosphorylation complexes

Mrpl35, A Mitospecific Component of Mitoribosomes, Plays A Key Role in Cytochrome \u3cem\u3eC\u3c/em\u3e Oxidase Assembly

Mitoribosomes perform the synthesis of the core components of the oxidative phosphorylation (OXPHOS) system encoded by the mitochondrial genome. We provide evidence that MrpL35 (mL38), a mitospecific component of the yeast mitoribosomal central protuberance, assembles into a subcomplex with MrpL7 (uL5), Mrp7 (bL27), and MrpL36 (bL31) and mitospecific proteins MrpL17 (mL46) and MrpL28 (mL40). We isolated respiratory defective mrpL35 mutant yeast strains, which do not display an overall inhibition in mitochondrial protein synthesis but rather have a problem in cytochrome coxidase complex (COX) assembly. Our findings indicate that MrpL35, with its partner Mrp7, play a key role in coordinating the synthesis of the Cox1 subunit with its assembly into the COX enzyme and in a manner that involves the Cox14 and Coa3 proteins. We propose that MrpL35 and Mrp7 are regulatory subunits of the mitoribosome acting to coordinate protein synthesis and OXPHOS assembly events and thus the bioenergetic capacity of the mitochondria

Exploring links between the social reform, nationalist, and women\u27s movements in India.

The investigation utilized a historical/comparative methodology to trace connections between three social movements---the Social Reform, Nationalist, and Women\u27s Movements in India. While some researchers (e.g. Tarrow (1994); Snow & Benford (1992)) offer the concept of the cultural and master frame to explain linkages between movements, this research went further by probing additional elements such as social networks and political career patterns. Connections were evident since all three were united through the master frame. The social reform movement laid the groundwork for both the nationalist and feminist movements. However, the impact of the reform and nationalist movement on Indian feminism was paradoxical. While both social reform and nationalism advanced the concerns of women, they also hindered the progress of the feminist movement through the propagation of contradictory roles and images of women. These movements also omitted certain feminist issues and thus many dissatisfied women mobilized their efforts to raise the status of women. Consequently, the master frame both empowered and limited movements. However, this cultural frame represented but one facet of the link between movements. An analysis of the life histories of women suggested that social networks and political career patterns also played a significant role in further connecting these movements.Dept. of Sociology and Anthropology. Paper copy at Leddy Library: Theses & Major Papers - Basement, West Bldg. / Call Number: Thesis1997 .S26. Source: Masters Abstracts International, Volume: 39-02, page: 0415. Adviser: Tanya Basok. Thesis (M.A.)--University of Windsor (Canada), 1998

A study on sustainability practices in the Malaysian Hospitality Industry

The hospitality industry encompasses an extensive variety of services that include food service, tourism and hotels. It can be considered a major service sector in the world economy today and described as an industry that has a great impact on the environment, discharging a huge amount of raw and solid waste, constituting a threat to the environment. While much as been done to promote tourism in Malaysia through activities such as Visit Malaysia Year (VMY), very little is done to ensure a sustainable development of the hospitality industry in Malaysia and the preservation of the natural environment for future generations. Of late, there is a growing concern on hotel organisations, as a sector of the tourism industry whose activities afflict the environment to start looking into its environmental impact. Therefore it is important that the hospitality sector in Malaysia consider more proactive measures in implementing sustainability practices in order to remain competitive globally or fail to compete with those designed as such. Some of the findings in this study have further clarified drivers and barriers that effect sustainable practices in the hospitality industry in Malaysia. It is hoped that findings from this research will add value to the existing body of knowledge and inspire policy makers and industry regulators to take the appropriate measures to ensure a sustainable growth of the hospitality industry and for the generations by supporting increased investment on implementing sustainable practices to conserve, preserve and protect the natural environment

GENETIC SUSCEPTIBILITY OF TRANSCRIPTION FACTOR 7-LIKE 2 GENE VARIANT AND RISK OF TYPE 2 DIABETES IN ASIAN INDIANS

Background: The variants of transcription factor 7-like 2 (TCF7L2) gene have been shown to be associated with type 2 diabetes mellitus (T2DM) and its related complications. Objectives: We aimed to explore the possible association of rs7903146 (C/T) variant in TCF7L2 with the risk of T2DM in the North Indian population. Methods: The present case–control study included a total of 638 human subjects (318 T2DM subjects and 320 healthy controls). Various anthropometric, biochemical, and genetic parameters were studies in all the subjects. Genotyping of TCF7L2 gene was carried out using allele-specific polymerase chain reaction method. Results: The results of this study indicate significantly higher values of body mass index, waist circumference, waist-to-hip ratio, and body fat (%) in T2DM subjects than controls (p≤0.001). Dyslipidemia represented by higher levels of triglycerides and reduced values of high-density lipoprotein was more predominant in diabetic subjects compared to healthy subjects. The frequency of risk genotype (TT) frequency was significantly higher in T2DM subjects (16.4%) compared to controls (11.6%). The “T” allele was more dominant in diabetic subjects than controls. Logistic regression analysis of the data revealed a significant association of TT genotype with 2-fold (odds ratio with 95% of confidence interval; 2.09 [1.29–3.42] p=0.003) and CT genotype with 1.7-fold (1.73 [1.23–2.44] p=0.002) increased risk of developing T2DM. Conclusions: The present study demonstrated a significant association of rs7903146 (C/T) variant in TCF7L2 with the augmented risk of T2DM in North Indian population

Multiple regression analysis for adoption studies of potato growers in Jammu division

The research identified the significant and negative relationship between socio-economic parameters with the level of adoption of recommended crop production technologies reveals that such information could be useful to Department of agriculture, and concerned SAU who strive to maximize production and productivity levels of potato crop. They have to gear-up there extension wings for imparting correct and scientific knowledge of crop production. It also suggested to State Govt. officials to ensure adequate facilities for fertilizers to reap full benefits of this cash crop. The study on determining the correlation between socio-economic standards of potato growers with the level of adoption of the recommended crop production technologies was conducted in sub-tropical zone of Jammu division. Three districts namely Jammu, Kathua and Samba were selected purposively on the basis of maximum area under potato crop. Sample size of 225 potato growers was selected randomly from 15 villages from selected districts and their socio-economic standards were correlated with the level of adoption of crop production technologies as recommended by SKUAST-JAMMU, the concerned SAU. The study revealed that age, education, operational land holding, net income, mass media exposure and extension contact had significant correlation at p? 0.05 level of probability with the level of adoption. Studies revealed that 45.78% of respondents adopted recommended seed rate per hectare, whereas 57.33%, 40.89% and 8.89% respondents adopted recommended application of nitrogen, phosphorus and potassium to the crop. The study further highlighted highest adoption level for insecticide like dimethoate 30 EC (52.05%) and fungicide like metalxyl +mancozeb (57.38%) respectively