Enzymes
Product List
PSMG4 Human
Proteasome Assembly Chaperone 4 Human Recombinant
PSMA2 Human
Proteasome Subunit Alpha Type 2 Human Recombinant
PSMA3 Human
Proteasome Subunit Alpha Type 3 Human Recombinant
PSMA4 Human
Proteasome Subunit Alpha Type 4 Human Recombinant
PSMA5 Human
Proteasome Subunit Alpha Type 5 Human Recombinant
PSMB10 Human
Proteasome Beta Type 10 Human Recombinant
PSMD5 Human
Proteasome 26S Subunit, Non-ATPase 5 Human Recombinant
PSMD9 Human
Proteasome 26S Subunit, Non-ATPase 9 Human Recombinant
PSME1 Human
Proteasome Activator Subunit 1 Human Recombinant
PSME2 Human
Proteasome Activator Subunit 2 Human Recombinant
Introduction
Proteasomes are large protein complexes found in eukaryotic cells, archaea, and some bacteria. They are responsible for degrading unneeded or damaged proteins by proteolysis, a chemical reaction that breaks peptide bonds . Proteasomes are classified into two main types: the 20S core particle and the 26S proteasome, which includes the 20S core particle capped with regulatory particles .
Key Biological Properties: Proteasomes are essential for maintaining cellular homeostasis by regulating the concentration of specific proteins and degrading misfolded proteins . They are involved in various cellular processes, including the cell cycle, gene expression regulation, and responses to oxidative stress .
Expression Patterns and Tissue Distribution: Proteasomes are ubiquitously expressed in all eukaryotic cells and are found in both the nucleus and cytoplasm . Their expression levels can vary depending on the cell type and physiological conditions .
Primary Biological Functions: The primary function of proteasomes is to degrade ubiquitin-tagged proteins, thereby regulating protein turnover and quality control within the cell . This process is crucial for removing damaged or misfolded proteins and preventing their accumulation .
Role in Immune Responses and Pathogen Recognition: Proteasomes play a vital role in the immune system by generating peptide fragments presented on major histocompatibility complex (MHC) class I molecules, which are recognized by cytotoxic T cells . This process is essential for the immune system to identify and eliminate infected or malignant cells .
Mechanisms with Other Molecules and Cells: Proteasomes interact with various molecules, including ubiquitin, which tags proteins for degradation . The 19S regulatory particle recognizes these ubiquitin-tagged proteins and directs them to the 20S core particle for degradation .
Binding Partners and Downstream Signaling Cascades: Proteasomes are involved in multiple signaling pathways by degrading key regulatory proteins, such as transcription factors and cyclins . This degradation process can activate or inhibit downstream signaling cascades, thereby influencing various cellular functions .
Regulatory Mechanisms Controlling Expression and Activity: Proteasome activity is tightly regulated at multiple levels, including transcriptional regulation, post-translational modifications, and changes in complex composition . For example, the expression of proteasome subunits can be upregulated in response to cellular stress .
Transcriptional Regulation and Post-Translational Modifications: Proteasome subunits are regulated at the transcriptional level by various transcription factors . Additionally, post-translational modifications, such as phosphorylation and ubiquitination, can modulate proteasome activity and stability .
Biomedical Research: Proteasomes are extensively studied in biomedical research for their role in protein homeostasis and disease pathogenesis . They are used as models to understand protein degradation mechanisms and develop therapeutic strategies .
Diagnostic Tools and Therapeutic Strategies: Proteasome inhibitors, such as bortezomib, are used as therapeutic agents in treating multiple myeloma and other cancers . These inhibitors block proteasome activity, leading to the accumulation of toxic proteins and inducing cell death in cancer cells .
Role Throughout the Life Cycle: Proteasomes are involved in various stages of the life cycle, from development to aging and disease . During development, they regulate the degradation of key proteins involved in cell differentiation and growth . In aging, proteasome activity declines, leading to the accumulation of damaged proteins and contributing to age-related diseases .
