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Subcellular Localization of Spx, YjbH, and ClpX in Bacillus subtilis under Normal Growth Conditions and Disulfide Stress

Sharifi, Elham (2012) MOBT18 20111
Degree Projects in Molecular Biology
Abstract
Popular science summary:

Monitoring subcellular localization of Spx, YjbH, and ClpX in Bacillus subtilis

Bacteria are exposed to continuous stress that causes damage to the cell. Therefore, they have developed stress responses that enable them to overcome stress and survive. Oxidizing elements is one kind of stress that bacteria have to deal with.

To investigate how bacteria cope with this kind of stress, Bacillus subtilis is used as a model organism. It has been found that B. subtilis has a protein called Spx which plays a role in the cellular response to oxidizing elements. The concentration of Spx istightly controlled by a protease complex called ClpXP. When the bacterium is not under stress and does not need Spx, ClpXP... (More)
Popular science summary:

Monitoring subcellular localization of Spx, YjbH, and ClpX in Bacillus subtilis

Bacteria are exposed to continuous stress that causes damage to the cell. Therefore, they have developed stress responses that enable them to overcome stress and survive. Oxidizing elements is one kind of stress that bacteria have to deal with.

To investigate how bacteria cope with this kind of stress, Bacillus subtilis is used as a model organism. It has been found that B. subtilis has a protein called Spx which plays a role in the cellular response to oxidizing elements. The concentration of Spx istightly controlled by a protease complex called ClpXP. When the bacterium is not under stress and does not need Spx, ClpXP degrades it. YjbH is an adaptor protein that is required for efficient ClpXP dependant degradation of Spx.

Bacterial cells have a highly organized internal architecture in which individual proteins localize to particular sites in the cell. Knowing where proteins are in the cell is often critical to understanding their function better. Therefore, investigation of the subcellular localization of Spx, YjbH and ClpX part of ClpXP complex, under both normal growth conditions and the stress, is of interest.

In this study I monitored localization of each of the respective proteins via fluorescence microscopy as fusions to variants of green fluorescence protein (GFP). Since GFP fluoresces, one can shine light at the cell that contains GFP by fluorescence microscope and wait for the distinctive green fluorescence associated with GFP to appear. By molecular technique, I joined the gene of GFP to the gene of the protein of interest so that when the protein is made, it has the GFP fused to it, which makes it possible to see where in the cell the protein is localized.

I observed that under normal growth conditions, Spx resides principally within nucleoid (where the genetic material is localized), YjbH is distributed all over the cytoplasm, and ClpX forms visible foci at polar and mid-cell region.

Advisors: Claes von Wachenfeldt
Master’s Degree Project in Molecular Microbiology, 60 credits
Department of Biology, Lund University (Less)
Please use this url to cite or link to this publication:
author
Sharifi, Elham
supervisor
organization
course
MOBT18 20111
year
type
H2 - Master's Degree (Two Years)
subject
language
English
id
3633171
date added to LUP
2013-04-12 12:36:27
date last changed
2013-04-12 12:36:27
@misc{3633171,
  abstract     = {Popular science summary:

Monitoring subcellular localization of Spx, YjbH, and ClpX in Bacillus subtilis 

Bacteria are exposed to continuous stress that causes damage to the cell. Therefore, they have developed stress responses that enable them to overcome stress and survive. Oxidizing elements is one kind of stress that bacteria have to deal with. 

To investigate how bacteria cope with this kind of stress, Bacillus subtilis is used as a model organism. It has been found that B. subtilis has a protein called Spx which plays a role in the cellular response to oxidizing elements. The concentration of Spx istightly controlled by a protease complex called ClpXP. When the bacterium is not under stress and does not need Spx, ClpXP degrades it. YjbH is an adaptor protein that is required for efficient ClpXP dependant degradation of Spx. 

Bacterial cells have a highly organized internal architecture in which individual proteins localize to particular sites in the cell. Knowing where proteins are in the cell is often critical to understanding their function better. Therefore, investigation of the subcellular localization of Spx, YjbH and ClpX part of ClpXP complex, under both normal growth conditions and the stress, is of interest. 

In this study I monitored localization of each of the respective proteins via fluorescence microscopy as fusions to variants of green fluorescence protein (GFP). Since GFP fluoresces, one can shine light at the cell that contains GFP by fluorescence microscope and wait for the distinctive green fluorescence associated with GFP to appear. By molecular technique, I joined the gene of GFP to the gene of the protein of interest so that when the protein is made, it has the GFP fused to it, which makes it possible to see where in the cell the protein is localized. 

I observed that under normal growth conditions, Spx resides principally within nucleoid (where the genetic material is localized), YjbH is distributed all over the cytoplasm, and ClpX forms visible foci at polar and mid-cell region. 

Advisors: Claes von Wachenfeldt 
Master’s Degree Project in Molecular Microbiology, 60 credits 
Department of Biology, Lund University},
  author       = {Sharifi, Elham},
  language     = {eng},
  note         = {Student Paper},
  title        = {Subcellular Localization of Spx, YjbH, and ClpX in Bacillus subtilis under Normal Growth Conditions and Disulfide Stress},
  year         = {2012},
}