Investigating the protein-protein Interaction between Aquaporin 4 & Calmodulin
(2020) KEMR45 20201Department of Chemistry
- Abstract
- Around 60 million people around the world are struggling with a traumatic brain or spinal cord injury. The swelling of the brain or spinal cord happen when the water content in the CNS increase due, infection, tumor growth or brain edema. AQP4 is a membrane water channel which mediates the water flux across the blood brain barrier (BBB) and blood spinal-cord barrier (BSCB). We believe that protein-protein interactions play crucial roles in regulating human Aquaporin’s by gating or trafficking, but the mechanism of how protein-protein interaction mediate water transport across the membrane remain poorly characterized. It has been suggested that AQP4 protein could be regulated by protein calmodulin through complicated and poorly... (More)
- Around 60 million people around the world are struggling with a traumatic brain or spinal cord injury. The swelling of the brain or spinal cord happen when the water content in the CNS increase due, infection, tumor growth or brain edema. AQP4 is a membrane water channel which mediates the water flux across the blood brain barrier (BBB) and blood spinal-cord barrier (BSCB). We believe that protein-protein interactions play crucial roles in regulating human Aquaporin’s by gating or trafficking, but the mechanism of how protein-protein interaction mediate water transport across the membrane remain poorly characterized. It has been suggested that AQP4 protein could be regulated by protein calmodulin through complicated and poorly characterized mechanism. It has been suggested that protein AQP4 is regulated by trafficking mechanism, through directly binding of CaM to AQP4.
In order to demonstrate this hypothesis, AQP4 was purified from P.pastoris cells and incorporated into nanodiscs. Activated CaM will be added to the nanodisc to study the binding mode between CaM and AQP4. The purified nanodisc, used for further analysis using Cryo-EM technology. By this technique we proved that AQP4 can bind to two calmodulin protein directly. (Less) - Popular Abstract
- Cells are the basic building blocks of all living organisms. There are organisms that are composed of a single cell, such as a bacterium or yeast, and some others could be composed of trillions of different cells such as animals or plants. If you look at the structure of these tiny cells using the microscope, you will figure out that these cells have many different parts and each part have different function. All these parts are essential for cell functioning. One of these parts is called the plasma membrane. It is made up of a lipid bilayer which separates the interior of the cells from the outside environment. This plasma membrane regulates the transportation of different material in and out of the cells, which means that this membrane... (More)
- Cells are the basic building blocks of all living organisms. There are organisms that are composed of a single cell, such as a bacterium or yeast, and some others could be composed of trillions of different cells such as animals or plants. If you look at the structure of these tiny cells using the microscope, you will figure out that these cells have many different parts and each part have different function. All these parts are essential for cell functioning. One of these parts is called the plasma membrane. It is made up of a lipid bilayer which separates the interior of the cells from the outside environment. This plasma membrane regulates the transportation of different material in and out of the cells, which means that this membrane is embedded tightly with lots of different channels and receptors. Water is an essential component of all living organisms and regulated water transportation is crucial for proper cell functioning. Aquaporin (AQP) is a small transmembrane water channel which facilitates water transport across the membrane. This channel is an open channel and needs to be regulated to function properly. This regulation could be happen upon a triggers such as, protein-protein interactions or other small molecules to force the AQPs to close or open the pore. It has been suggested that tumor cells express the AQPs and there is a direct relation
between histological tumors and the number of AQPs expressed in the membrane compared to normal tissues. This make the AQPs interesting proteins to be investigated to understand how they function and how they could be regulated after discovering their structure. Until now 13 different AQP have been discovered, each being expressed in different tissues. AQP4 is one type of human AQP which is mostly expressed in astrocytes and which mediates the water flux across the BBB and BSCB. In this project we overexpressed AQP4 and used it to find if this protein could be regulated by the protein calmodulin. This was done by incorporating AQP4 into nanodiscs and using these nanodiscs for complex formation of AQP4-CaM. This complex formation was confirmed by Cryo-EM to show that calmodulin could bind to AQP4 with a ratio of 1:2 (AQP4:CaM). (Less)
Please use this url to cite or link to this publication:
http://lup.lub.lu.se/student-papers/record/9028898
- author
- Majhool, Zahraa LU
- supervisor
- organization
- course
- KEMR45 20201
- year
- 2020
- type
- H1 - Master's Degree (One Year)
- subject
- keywords
- aquaporin4"protein-protein, interaction"calmodulin", biochemistry, molecular biology, biokemi, molekylärbiologi
- report number
- 1
- language
- English
- id
- 9028898
- date added to LUP
- 2020-11-09 09:22:29
- date last changed
- 2020-11-09 09:23:05
@misc{9028898,
abstract = {{Around 60 million people around the world are struggling with a traumatic brain or spinal cord injury. The swelling of the brain or spinal cord happen when the water content in the CNS increase due, infection, tumor growth or brain edema. AQP4 is a membrane water channel which mediates the water flux across the blood brain barrier (BBB) and blood spinal-cord barrier (BSCB). We believe that protein-protein interactions play crucial roles in regulating human Aquaporin’s by gating or trafficking, but the mechanism of how protein-protein interaction mediate water transport across the membrane remain poorly characterized. It has been suggested that AQP4 protein could be regulated by protein calmodulin through complicated and poorly characterized mechanism. It has been suggested that protein AQP4 is regulated by trafficking mechanism, through directly binding of CaM to AQP4.
In order to demonstrate this hypothesis, AQP4 was purified from P.pastoris cells and incorporated into nanodiscs. Activated CaM will be added to the nanodisc to study the binding mode between CaM and AQP4. The purified nanodisc, used for further analysis using Cryo-EM technology. By this technique we proved that AQP4 can bind to two calmodulin protein directly.}},
author = {{Majhool, Zahraa}},
language = {{eng}},
note = {{Student Paper}},
title = {{Investigating the protein-protein Interaction between Aquaporin 4 & Calmodulin}},
year = {{2020}},
}