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Protein-protein interactions studied by the bacterial two-hybrid system (BACTH)

Taki, Laila (2017) MOBK01 20162
Degree Projects in Molecular Biology
Popular Abstract
The color of proteins

Proteins are crucial for many functions in the cell, and it is especially important when two proteins interact. Protein-protein interaction (PPI) is when two proteins come together, and then the interaction or interplay between them can be visualized or measured. These interactions control structures such as the ones that give cells their shapes. If we imagine a cell in which the specific PPIs would disappear, this cell would become deaf and blind, and it could simply collapse because these specific interactions are involved in almost every physiological process.

PPIs can be studied by a system that is based on the repair of an enzyme* in bacteria that lacks this enzyme. The enzyme has two sites that will... (More)
The color of proteins

Proteins are crucial for many functions in the cell, and it is especially important when two proteins interact. Protein-protein interaction (PPI) is when two proteins come together, and then the interaction or interplay between them can be visualized or measured. These interactions control structures such as the ones that give cells their shapes. If we imagine a cell in which the specific PPIs would disappear, this cell would become deaf and blind, and it could simply collapse because these specific interactions are involved in almost every physiological process.

PPIs can be studied by a system that is based on the repair of an enzyme* in bacteria that lacks this enzyme. The enzyme has two sites that will restore the enzyme activity in the bacteria that lacks it when the proteins we want to study are put into the sites, but only if there is an interaction between the proteins. What this enzyme does, is that it will convert the energy of the cell into something else only when the enzyme is activated. The interaction can be visualized when the proteins inserted into bacteria grows on different types of plates with different nutrients. Here, we tested this system with four different types of proteins.

Screening on plates
We could visualize the PPIs on the different types of plates by looking at the color of the bacteria that grew on them. For Plate 1, an interaction could be seen when the bacteria turned red, as it remained colorless if there was no interaction. This plate created a few deviations, such as less growth, as the nutrients in it is not what the bacterium normally favors. The second plate was more reliable, as the bacteria would not grow on it unless there was a PPI, which could be seen when the bacteria turned blue. As for the third type of plate, a PPI could be visualized if the bacteria turned blue/green, but similarly to Plate 1 if it remained colorless there was no PPI.

How did we know what to expect? Based on previous studies, we already knew which proteins we expected to interact together. However, our results indicated otherwise. The reason for this deviation could be that we only observed PPI visually. Therefore, to obtain more reliable results, we should instead measure the intensity of the PPI.

Finally, you might think that this is cool, but why is it important? By studying protein-protein interactions, we can get one step closer to understanding the function and behavior of a certain protein, and thus the importance of it in a cell.

Supervisor: Claes von Wachenfeldt
Degree project, 15 credits
Department of Biology, Lund University (Less)
Please use this url to cite or link to this publication:
author
Taki, Laila
supervisor
organization
course
MOBK01 20162
year
type
M2 - Bachelor Degree
subject
language
English
id
8902198
date added to LUP
2017-02-02 15:01:05
date last changed
2017-02-02 15:01:05
@misc{8902198,
  author       = {Taki, Laila},
  language     = {eng},
  note         = {Student Paper},
  title        = {Protein-protein interactions studied by the bacterial two-hybrid system (BACTH)},
  year         = {2017},
}