PSMA3

Overview

PSMA3 (Proteasome Subunit Alpha Type-3) is a protein that in humans is encoded by the PSMA3 gene. It is a component of the 20S core proteasome complex, which is involved in the degradation of ubiquitinated proteins. This process is crucial for maintaining cellular protein homeostasis by removing damaged or misfolded proteins and regulating the concentration of specific proteins to control various cellular processes.

Structure

The PSMA3 protein is part of the alpha subunit family of the proteasome complex. The 20S proteasome core is composed of 28 subunits arranged in four stacked rings, forming a barrel-shaped structure. The two outer rings consist of seven alpha subunits, including PSMA3, while the two inner rings consist of seven beta subunits. The alpha subunits, including PSMA3, play a role in the gating of the proteasome, controlling the entry of substrates into the proteolytic chamber.

Function

PSMA3, as part of the proteasome complex, is involved in the ATP-dependent degradation of ubiquitinated proteins. This degradation process is essential for various cellular processes, including:

• Cell cycle regulation
• Apoptosis
• DNA repair
• Signal transduction
• Antigen processing for immune response

The proteasome degrades proteins by breaking peptide bonds, a process that is tightly regulated and essential for cellular function and survival.

Clinical Significance

Alterations in proteasome function, including mutations or dysregulation of PSMA3, have been implicated in various diseases, such as:

• Cancer: Abnormal proteasome activity can lead to uncontrolled cell proliferation and tumor development.
• Neurodegenerative diseases: Impaired protein degradation is a hallmark of diseases like Alzheimer's disease and Parkinson's disease.
• Autoimmune diseases: Dysregulation of antigen processing can affect immune tolerance and lead to autoimmune conditions.

Research and Therapeutic Implications

The proteasome, including PSMA3, is a target for therapeutic intervention. Proteasome inhibitors, such as bortezomib, are used in the treatment of multiple myeloma and certain types of lymphoma. These inhibitors work by blocking the proteolytic activity of the proteasome, leading to the accumulation of proteins that induce apoptosis in cancer cells.

Also see

• Proteasome
• Ubiquitin-proteasome system
• Protein degradation
• PSMA1
• PSMA2

References

Template:Proteasome

PSMA3
Identifiers
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