Ubiquitin Proteasome System Explained/ Ubiquitin Proteasome Pathway in eukaryotes
3.9 هزار بار بازدید -
4 سال پیش
-
#genetics
#genetics #biotechnology #proteindegradation #cellsignaling
Today, we are diving deep into the fascinating world of cellular biology to explore the intricate machinery known as the Ubiquitin Proteasome System. Buckle up and get ready to unlock the secrets of this remarkable system. This is the last video (13th) in the series of videos on cell cycle/cell division and the link to the other 12 videos are the following
Part 1: Overview of cell cycle/cell division
An overview of cell cycle/cell divisi...
Cell cycle/Cell Division; Machinery of the cell cycle (Part 2 of the cell cycle)
Machinery of the cell cycle /Cell Div...
Cell Cycle Control System/Cell Division Control System (Part 3 of the cell cycle)
Cyclins and Cyclin-dependent Kinases ...
Cell cycle/cell division (Part 4); Events in the G1 phase of the cell cycle
Cyclin Dependent Kinase 4 (CDK-4) and...
Cell cycle/Cell division (Part 5): Role of p53
p53, a tumor suppressor protein (cell...
Cell cycle/Cell division (Part 6); Functions of CDKs; G1-S and S-cdk
Functions of Cyclin-Dependent Kinases...
Cell cycle/cell division (Part 7); Events in the S and G2 Phase
Function of S-CDK and M-CDK; S and G2...
Cell cycle/cell division (Part 8); G2 phase as a preparatory phase for the M phase
How the M-CDK (complex of Cyclin-depe...
Cell cycle/ cell division(Part 9); functions of M-CDK (CDK1+ Cyclin B)
Functions of M-CDK (CDK1+ Cyclin B) (...
Cell cycle/Cell division (Part 10); Events in the metaphase
Metaphase of the Cell cycle (Mitosis)...
Cell cycle/cell division (Part 11); Role of spindle assembly checkpoint
Role of spindle assembly checkpoint i...
Cell cycle/cell division (Part 12); functions of Anaphase promoting complex and contractile ring
L12: Functions of Anaphase promoting ...
The Ubiquitin Proteasome System, or UPS for short, is a finely tuned mechanism found in eukaryotic cells that regulates the degradation and recycling of proteins. Just like a diligent janitor, it ensures the cellular environment remains clean and functional.
To understand how this system works, let's break it down into its three main players:
a. Ubiquitin: a small protein found in all eukaryotic cells, acts as a molecular tag to mark specific proteins for degradation.
b. E1, E2, and E3 enzymes
c. Proteasome.
The first step of the process involves E1 enzymes, or ubiquitin-activating enzymes. These enzymes activate ubiquitin by attaching it to themselves, forming a high-energy thioester bond. Once activated, ubiquitin is transferred to E2 enzymes, or ubiquitin-conjugating enzymes. E2 enzymes work in tandem with E3 enzymes, or ubiquitin ligases, to recognize target proteins and attach ubiquitin molecules to them. Here's where the specificity of the UPS comes into play. Different E3 ligases recognize specific proteins, allowing for precise targeting. Think of E3 ligases as the molecular matchmakers, pairing the ubiquitin tag with the right protein.
As the ubiquitin chain grows, it serves as a signal to guide the marked protein to its fate: degradation by the proteasome. The proteasome, a large protein complex, acts as a cellular recycling plant, dismantling tagged proteins into smaller peptides.
The proteasome consists of a barrel-shaped core particle, known as the 20S proteasome, flanked by regulatory particles. These regulatory particles help recognize ubiquitin-tagged proteins and unfold them, allowing entry into the 20S core for degradation. Within the 20S proteasome, proteolytic activities cleave the tagged protein into short peptides. These peptides are then released and can be further degraded or recycled for various cellular processes.
It's important to note that the UPS not only eliminates damaged or misfolded proteins but also controls the levels of specific regulatory proteins. By marking proteins for degradation, the UPS exerts precise control over cellular processes such as cell cycle progression, DNA repair, and immune responses.
However, the UPS is not infallible. Dysregulation of this system has been implicated in various diseases, including cancer, neurodegenerative disorders like Alzheimer's and Parkinson's, and autoimmune conditions. Scientists have made tremendous strides in understanding the Ubiquitin Proteasome System and its implications. Ongoing research aims to unravel the intricate details of its functioning and discover new therapeutic avenues for diseases associated with UPS malfunction. So, the next time you admire the remarkable complexity of cellular machinery, remember the unsung hero, the Ubiquitin Proteasome System, working tirelessly behind the scenes to maintain the homeostasis of proteins.
Today, we are diving deep into the fascinating world of cellular biology to explore the intricate machinery known as the Ubiquitin Proteasome System. Buckle up and get ready to unlock the secrets of this remarkable system. This is the last video (13th) in the series of videos on cell cycle/cell division and the link to the other 12 videos are the following
Part 1: Overview of cell cycle/cell division
An overview of cell cycle/cell divisi...
Cell cycle/Cell Division; Machinery of the cell cycle (Part 2 of the cell cycle)
Machinery of the cell cycle /Cell Div...
Cell Cycle Control System/Cell Division Control System (Part 3 of the cell cycle)
Cyclins and Cyclin-dependent Kinases ...
Cell cycle/cell division (Part 4); Events in the G1 phase of the cell cycle
Cyclin Dependent Kinase 4 (CDK-4) and...
Cell cycle/Cell division (Part 5): Role of p53
p53, a tumor suppressor protein (cell...
Cell cycle/Cell division (Part 6); Functions of CDKs; G1-S and S-cdk
Functions of Cyclin-Dependent Kinases...
Cell cycle/cell division (Part 7); Events in the S and G2 Phase
Function of S-CDK and M-CDK; S and G2...
Cell cycle/cell division (Part 8); G2 phase as a preparatory phase for the M phase
How the M-CDK (complex of Cyclin-depe...
Cell cycle/ cell division(Part 9); functions of M-CDK (CDK1+ Cyclin B)
Functions of M-CDK (CDK1+ Cyclin B) (...
Cell cycle/Cell division (Part 10); Events in the metaphase
Metaphase of the Cell cycle (Mitosis)...
Cell cycle/cell division (Part 11); Role of spindle assembly checkpoint
Role of spindle assembly checkpoint i...
Cell cycle/cell division (Part 12); functions of Anaphase promoting complex and contractile ring
L12: Functions of Anaphase promoting ...
The Ubiquitin Proteasome System, or UPS for short, is a finely tuned mechanism found in eukaryotic cells that regulates the degradation and recycling of proteins. Just like a diligent janitor, it ensures the cellular environment remains clean and functional.
To understand how this system works, let's break it down into its three main players:
a. Ubiquitin: a small protein found in all eukaryotic cells, acts as a molecular tag to mark specific proteins for degradation.
b. E1, E2, and E3 enzymes
c. Proteasome.
The first step of the process involves E1 enzymes, or ubiquitin-activating enzymes. These enzymes activate ubiquitin by attaching it to themselves, forming a high-energy thioester bond. Once activated, ubiquitin is transferred to E2 enzymes, or ubiquitin-conjugating enzymes. E2 enzymes work in tandem with E3 enzymes, or ubiquitin ligases, to recognize target proteins and attach ubiquitin molecules to them. Here's where the specificity of the UPS comes into play. Different E3 ligases recognize specific proteins, allowing for precise targeting. Think of E3 ligases as the molecular matchmakers, pairing the ubiquitin tag with the right protein.
As the ubiquitin chain grows, it serves as a signal to guide the marked protein to its fate: degradation by the proteasome. The proteasome, a large protein complex, acts as a cellular recycling plant, dismantling tagged proteins into smaller peptides.
The proteasome consists of a barrel-shaped core particle, known as the 20S proteasome, flanked by regulatory particles. These regulatory particles help recognize ubiquitin-tagged proteins and unfold them, allowing entry into the 20S core for degradation. Within the 20S proteasome, proteolytic activities cleave the tagged protein into short peptides. These peptides are then released and can be further degraded or recycled for various cellular processes.
It's important to note that the UPS not only eliminates damaged or misfolded proteins but also controls the levels of specific regulatory proteins. By marking proteins for degradation, the UPS exerts precise control over cellular processes such as cell cycle progression, DNA repair, and immune responses.
However, the UPS is not infallible. Dysregulation of this system has been implicated in various diseases, including cancer, neurodegenerative disorders like Alzheimer's and Parkinson's, and autoimmune conditions. Scientists have made tremendous strides in understanding the Ubiquitin Proteasome System and its implications. Ongoing research aims to unravel the intricate details of its functioning and discover new therapeutic avenues for diseases associated with UPS malfunction. So, the next time you admire the remarkable complexity of cellular machinery, remember the unsung hero, the Ubiquitin Proteasome System, working tirelessly behind the scenes to maintain the homeostasis of proteins.
4 سال پیش
در تاریخ 1399/04/20 منتشر شده
است.
3,918
بـار بازدید شده