The Effect of Culture Medium Composition on the Localization of Peroxisomal Membrane Proteins in Yeast

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Authors
Miller, Maria
Advisor
John Addis
Gerald Shields
Murphy Fox
Editor
Date of Issue
2009-04-01
Subject Keywords
peroxisomes, yeast
Publisher
Citation
Series/Report No.
item.page.identifier
Title
The Effect of Culture Medium Composition on the Localization of Peroxisomal Membrane Proteins in Yeast
Other Titles
Type
thesis
Description
Abstract
Formation and degradation of peroxisomes are not well understood, but their absence leads to serious consequences. In the study described in this thesis, 1 sought to (1) verify previous work indicating that switching from glucose-rich medium to lipid-rich medium induces peroxisome formation; (2) reveal that switching back from lipid-rich to glucose-rich medium induces peroxisome degradation; (3) test the hypothesis that Pex3p is a class II PMP that enters the peroxisome from the endoplasmic reticulum during de novo peroxisome formation; and (4) test the hypothesis that Pxalp is a class I PMP that enters the peroxisomal membrane from the cytosol. I followed the pattern of fluorescence in yeast cells expressing Pex3p-Green Fluorescent Protein (GFP) and Pxalp-GFP fusion proteins after cells were transferred either from a glucose-rich to a lipid- rich medium or vice versa. I succeeded in producing GFP transformants for two peroxisome genes. I also confirmed that switching to lipid-rich medium induced peroxisome formation and demonstrated that switching the peroxisomes back into the glucose medium triggered a rapid degradation. Evidence consistent with the hypotheses that Pex3p moves from the ER to the peroxisomal membrane and that Pxalp is transported from the cytosol to the membrane was obtained, but the overall support was weak.
Sponsors
Degree Awarded
Bachelor's
Semester
Spring
Department
Life & Environmental Sciences