Related Experiment Video
Updated: Aug 8, 2026
15:35
Analyzing Large Protein Complexes by Structural Mass Spectrometry
Published on: June 19, 2010
The complete primary structure of mouse 20S proteasomes
L A Elenich1, D Nandi, A E Kent
1Howard Hughes Medical Institute, and Departments of Molecular Genetics and Cell Biology, University of Cincinnati, 231 Bethesda Avenue, Cincinnati, OH 45267-0524, USA.
Immunogenetics
|August 7, 1999
Summary
Researchers have fully cloned all mouse proteasome subunits, crucial for generating peptides presented by MHC class I molecules. This completes the genetic characterization of these essential protein complexes in mice.
Area of Science:
- Molecular Biology
- Immunology
- Proteomics
Background:
- The proteasome is a key multicatalytic proteinase involved in peptide generation for MHC class I presentation.
- Mammalian 20S proteasome cores consist of 17 protein subunits, identifiable by unique 2D gel electrophoresis patterns.
- Genes for many human and rat proteasome subunits have been identified.
Purpose of the Study:
- To complete the cloning of all mouse proteasome subunits.
- To identify and characterize the mouse orthologues of proteasome subunits.
Main Methods:
- Isolation of cDNA clones for ten mouse proteasome subunits.
- Verification of protein identity using antisera and two-dimensional NEPHGE-PAGE.
Main Results:
- Successfully isolated cDNA clones for ten mouse proteasome subunits: PSMA1, PSMA2, PSMA3, PSMA4, PSMA5, PSMA6, PSMA7, PSMB2, PSMB3, and PSMB5.
- Completed the cloning of all known mouse proteasome subunits.
- Confirmed the identity of these proteins using specific antisera and advanced gel electrophoresis techniques.
Conclusions:
- The cloning of these ten subunits signifies the complete genetic characterization of mouse proteasome subunits.
- This comprehensive cloning effort provides essential tools for further research into proteasome function in mice.
- The findings facilitate deeper understanding of antigen presentation pathways involving the proteasome.
Related Concept Videos
02:41Protein Complex Assembly
Proteins can form homomeric complexes with another unit of the same protein or heteromeric complexes with different types. Most protein complexes self-assemble spontaneously via ordered pathways, while some proteins need assembly factors that guide their proper assembly. Despite the crowded intracellular environment, proteins usually interact with their correct partners and form functional complexes.
Many viruses self-assemble into a fully functional unit using the infected host cell to...
Many viruses self-assemble into a fully functional unit using the infected host cell to...
02:18The Proteasome
Eukaryotic cells can degrade proteins through several pathways. One of the most important amongst these is the ubiquitin-proteasome pathway. It helps the cell eliminate the misfolded, damaged, or unwarranted cytoplasmic proteins in a highly specific manner.
In this pathway, the target proteins are first tagged with small proteins called ubiquitin. A series of enzymes carry out the ubiquitination of the target proteins - E1 (ubiquitin-activating enzyme), E2 (ubiquitin-conjugating enzyme), and E3...
In this pathway, the target proteins are first tagged with small proteins called ubiquitin. A series of enzymes carry out the ubiquitination of the target proteins - E1 (ubiquitin-activating enzyme), E2 (ubiquitin-conjugating enzyme), and E3...
01:24Protein Organization
Proteins are polymers of amino acid residues. They are versatile and responsible for different cellular functions, including DNA replication, molecular transport, catalysis, and structural support. Proteins have a hierarchical structure comprising at least three levels of organization: primary, secondary, and tertiary structure. Some large proteins have a quaternary structure where individual protein subunits are linked together.
The primary structure of a protein is its amino acid sequence.
The primary structure of a protein is its amino acid sequence.
02:18The Proteasome
Eukaryotic cells can degrade proteins through several pathways. One of the most important amongst these is the ubiquitin-proteasome pathway. It helps the cell eliminate the misfolded, damaged, or unwarranted cytoplasmic proteins in a highly specific manner.
In this pathway, the target proteins are first tagged with small proteins called ubiquitin. A series of enzymes carry out the ubiquitination of the target proteins - E1 (ubiquitin-activating enzyme), E2 (ubiquitin-conjugating enzyme), and E3...
In this pathway, the target proteins are first tagged with small proteins called ubiquitin. A series of enzymes carry out the ubiquitination of the target proteins - E1 (ubiquitin-activating enzyme), E2 (ubiquitin-conjugating enzyme), and E3...
01:13The Proteasome
Eukaryotic cells can degrade proteins through several pathways. One of the most important among these is the ubiquitin-proteasome pathway. It helps the cell eliminate the misfolded, damaged, or unwarranted cytoplasmic proteins in a highly specific manner.
In this pathway, the target proteins are first tagged with small proteins called ubiquitin. This involves participation of a series of enzymes including— E1 (ubiquitin-activating enzyme), E2 (ubiquitin-conjugating enzyme), and E3 (ubiquitin...
In this pathway, the target proteins are first tagged with small proteins called ubiquitin. This involves participation of a series of enzymes including— E1 (ubiquitin-activating enzyme), E2 (ubiquitin-conjugating enzyme), and E3 (ubiquitin...
01:17The Proteasome Structure
The ubiquitin-proteasome pathway is a well-known mechanism utilized by eukaryotic cells to remove cytoplasmic proteins that are misfolded, damaged, or no longer needed. In this pathway, the protein that needs to be eliminated undergoes a process called ubiquitination, where a chain of ubiquitin molecules is attached to the 48th lysine residue of the target protein. This ubiquitin modification helps the proteasome distinguish between a target protein and a healthy protein.
The proteasome is an...
The proteasome is an...