CD74
GeneName
CD74
Summary
CD74, also known as the Ii chain or MHC class II associated invariant chain, is a 34kDa type II transmembrane protein primarily expressed on antigen-presenting cells, including macrophages, dendritic cells, and B cells. It plays a crucial role in the immune system by facilitating the proper folding and transport of MHC class II molecules, ensuring their stability and preventing premature peptide loading in the endoplasmic reticulum. CD74 is involved in various cellular compartments such as the plasma membrane, endosomes, lysosomes, and the Golgi apparatus. Additionally, it has functions in cytokine binding and macrophage migration inhibitory factor binding, contributing to various signalling pathways that regulate immune responses.
Importance
CD74 is relevant to: - Antigen presentation and immune response modulation through its role in MHC class II molecule stability and peptide loading - Regulation of macrophage activation and migration, impacting inflammation and immune responses - Its involvement in cytokine-mediated signalling pathways, influencing various immune cell functions - Potential implications in autoimmune diseases and cancer, given its role in immune cell interactions and T cell activation
Top Products
For researchers investigating CD74, we recommend two excellent primary antibodies. The first is the well-cited Anti-CD74 antibody [LN2] (ab9514), a monoclonal antibody that has garnered 29 citations, reflecting its reliability in the field. This antibody is validated for use in immunohistochemistry (IHC), flow cytometry (FC), and western blotting (WB), making it a versatile choice for various applications. Importantly, it has also been validated in knockout models, ensuring its effectiveness in specific experimental contexts.Additionally, we offer the recombinant Anti-CD74 antibody [EPR4064] (ab108393), which is suitable for a broader range of applications, including IHC, FC, WB, immunocytochemistry (ICC), and ELISA. This recombinant antibody has been validated in knockout models as well, providing researchers with the batch-to-batch consistency that is often essential for reproducible results. With 5 citations, it is gaining traction among scientists studying CD74. Together, these antibodies provide robust options for your research needs. The Human CD74 ELISA Kit (ab284618) is an excellent option for researchers looking to measure CD74 levels in their samples.
Abcam Product Citation Summary
The data indicates that CD74 is being studied in the context of human primary tumours and brain metastatic melanoma. The use of immunohistochemistry and Western blot suggests a focus on understanding the role of CD74 in cancer biology.
Abcam Product Citation Table
Domain
Antiviral activity requires delivery of the thyroglobulin domain to the endosomal membrane.
Function
Plays a critical role in MHC class II antigen processing by stabilizing peptide-free class II alpha/beta heterodimers in a complex soon after their synthesis and directing transport of the complex from the endoplasmic reticulum to the endosomal/lysosomal system where the antigen processing and binding of antigenic peptides to MHC class II takes place. Serves as cell surface receptor for the cytokine MIF.
Class-II-associated invariant chain peptide
Binds to the peptide-binding site of MHC class II alpha/beta heterodimers forming an alpha-beta-CLIP complex, thereby preventing the loading of antigenic peptides to the MHC class II complex until its release by HLA-DM in the endosome.
Isoform p41
Stabilizes the conformation of mature CTSL by binding to its active site and serving as a chaperone to help maintain a pool of mature enzyme in endocytic compartments and extracellular space of antigen-presenting cells (APCs). Has antiviral activity by stymieing the endosomal entry of Ebola virus and coronaviruses, including SARS-CoV-2 (PubMed:32855215). Disrupts cathepsin-mediated Ebola virus glycoprotein processing, which prevents viral fusion and entry. This antiviral activity is specific to p41 isoform (PubMed:32855215).
Involvement in disease
A chromosomal aberration involving CD74 is found in a non-small cell lung tumor. Results in the formation of a CD74-ROS1 chimeric protein.
Post-translational modifications
O-glycosylated with core 1 or possibly core 8 glycans (PubMed:22171320, PubMed:23234360). Contains chondroitin sulfate (PubMed:25326458).
Tissue Specificity
Detected in urine (at protein level).
Isoform p41
In B cells, represents 10% of total CD74 expression.
Isoform p33
In B cells, represents 70% of total CD74 expression.
Cellular localization
- Cell membrane
- Single-pass type II membrane protein
- Endoplasmic reticulum membrane
- Golgi apparatus
- trans-Golgi network
- Endosome
- Lysosome
- Secreted
- Transits through a number of intracellular compartments in the endocytic pathway. It can either undergo proteolysis or reach the cell membrane.
- Isoform p41
- Late endosome
- Lysosome
Alternative names
CD74, DHLAG, HLA class II histocompatibility antigen gamma chain, HLA-DR antigens-associated invariant chain, Ia antigen-associated invariant chain, Ii
Database links
swissprot:P04233 omim:142790 entrezGene:972
Other research areas
- Immuno-oncology