Cd74

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 compartments where peptide loading of class II takes place. Enhance also the stimulation of T-cell responses through interaction with CD44.

Isoform Long

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).

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.

Tissue Specificity

Isoform Long

Expressed in thymus and lymph noodes (PubMed:8977190). Expressed by antigen-presenting cells (APCs) (PubMed:11483509, PubMed:12417635).

Isoform Short

Expressed in thymus and lymph noodes.

Cellular localization

• Isoform Long
• Late endosome
• Lysosome
• 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.

Alternative names

CD74, Ii, Cd74, H-2 class II histocompatibility antigen gamma chain, Ia antigen-associated invariant chain, MHC class II-associated invariant chain, Ii chain

Database links

swissprot:P04441 entrezGene:16149

Other research areas

• Immuno-oncology