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| Author(s): |
Raquel Fonseca Guedes Monteiro
Total Authors: 1
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| Document type: | Doctoral Thesis |
| Press: | São Paulo. |
| Institution: | Universidade de São Paulo (USP). Instituto de Ciências Biomédicas (ICB/SDI) |
| Defense date: | 2017-09-05 |
| Examining board members: |
Mário Henrique de Barros;
Fernanda Marques da Cunha;
Rodrigo da Silva Galhardo;
Luis Eduardo Soares Netto;
Erich Birelli Tahara
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| Advisor: | Mário Henrique de Barros |
| Abstract | |
One of the reasons that turn Saccharomyces cerevisiae a model organism is the degree of conservation of cellular mechanisms that exist between this yeast and higher eukaryotes. However, even after 21 years of sequencing their genome, there are still more than 600 ORFs with unknown function. In this work, we selected four of them for the detailed study. MRPL34 (YDR115w) is present in the major subunit of the yeast mitochondrial ribosome and bears similarity to the L34 gene of E. coli and MRP-L34 from humans. The Δ mrpl34 mutant shows unstable mitochondrial DNA (mtDNA) and to study it, temperature sensitive alleles (ts) were generated. With the mitochondrial protein synthesis assays in vivo, it was possible to identify a clear decrease in the protein synthesis of the conditional mutant. Mrpl34p was identified in the ribosomal extract as expected. The disassembly of the major subunit of the mitochondrial ribosome, using the ts mutants, provided us some clues about intermediates in its assembly process. We have verified that the N-terminal portion of the protein is responsible for addressing the mitochondria. YPR116w also shows high mitochondrial DNA instability, in this way, thermosensitive mutants were used in the experiments. One of the strategies used was the search for genetic partners. We verified that ylr091wp increases the stability of ts-ypr116w mtDNA, suggesting suppressor activity. We also found that the ts-ypr16w allele has a smaller amount of mitochondrial tRNA, through Northen blot assays. Two of the chosen ORFs (YDL119c and YOR022c) had their initial characterization published in 2016, reflecting the importance of this type of research. We have seen that the protein encoded by YDL119c is located on the inner membrane of the mitochondria and that the Δyor022c mutant presents reduced amounts of cardiolipin when grown at 37 ºC. (AU) | |
| FAPESP's process: | 11/18892-0 - Characterization of mitochondrial gene products with unknown function in Saccharomyces cerevisiae. |
| Grantee: | Raquel Fonseca Guedes Monteiro |
| Support Opportunities: | Scholarships in Brazil - Doctorate |