Characterisation of peroxisomes in the fission Yeast Schizosaccharomyces pombe and slime mold Dictyostelium discoideum

dc.contributor.advisorKing, Jason
dc.contributor.advisorHettema, Ewald
dc.contributor.advisorWatts, Donald
dc.contributor.authorAlhammad, Yousef Mohammed A.
dc.date.accessioned2024-02-07T11:32:45Z
dc.date.available2024-02-07T11:32:45Z
dc.date.issued2024-02-05
dc.description.abstractPeroxisome is a compartment that is found in most eukaryotic organisms' cells. It has several crucial roles, such as fatty acid beta (β) oxidation and hydrogen peroxide (H2O2) detoxification. It contains many essential enzymes, including oxidase and catalase, and has several metabolic and non-metabolic pathways, depending on the environment and the organisms within its cells. This study investigates the role of peroxisomes in two organisms, S. pombe and D. discoideum. Although S. pombe is a well-studied yeast, there is only one study of this yeast that has focused on peroxisomes. This study offers a few crucial observations, including that S. pombe contains peroxisomes, that GFP containing a well-characterized PTS1 (SKL) is efficiently imported, and that peroxisome numbers increase in cells grown on a fatty acid as the sole carbon source, suggesting a role for peroxisomes in fatty acid degradation. The starting point in my research was initially a bioinformatics screen. This screening recognized the enzymes imported into peroxisomes based on the presence of a potential peroxisomal targeting signal. A few proteins were found. However, the low number of proteins with a classical PTS might be the result of different targeting signals that are not recognized by our bioinformatics parameters. Indeed, in other organisms, there are proteins without PTS1 that still use Pex5 for import. The first example is S. cerevisiae Acyl-CoA oxidase. In a global yeast two-hybrid screen, S. pombe Pex5 was found to bind S. pombe Str3 and Lys3. Consequently, we think that there is conserved targeting of a peroxisomal protein lacking a PTS1 and PTS2 imported into the peroxisome by Pex5. One of these is the Str3 case. Interestingly, proteins involved in peroxisomal fatty acid β -oxidation are absent from the S. pombe genome, casting doubt on the conclusions from the previous study and explaining the low number of potential peroxisomal enzymes. In D. discoideum, this study investigates the dynamic regulation of peroxisome numbers in response to growth conditions and identifies peroxisomal import and contents through a proximity labeling approach (BioID). Overall, this study sheds light on the roles and regulation of peroxisomes in these two organisms.
dc.format.extent312
dc.identifier.urihttps://hdl.handle.net/20.500.14154/71392
dc.language.isoen
dc.publisherUniversity of Sheffield
dc.subjectPeroxisome
dc.subjectproximity labeling approach (BioID)
dc.subjectYeasts
dc.subjectfatty acid β -oxidation
dc.subjectSchizosaccharomyces pombe
dc.subjectDictyostelium discoideum
dc.subjectBioinformatics
dc.subjectSaccharomyces Cerevisiae
dc.titleCharacterisation of peroxisomes in the fission Yeast Schizosaccharomyces pombe and slime mold Dictyostelium discoideum
dc.typeThesis
sdl.degree.departmentScience
sdl.degree.disciplineMolecular Biology and Biotechnology
sdl.degree.grantorUniversity of Sheffield
sdl.degree.nameDoctor of Philosophy

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