CD74/DHLAG (CD74) Active Protein

The protein encoded by this gene associates with class II major histocompatibility complex (MHC) and is an important chaperone that regulates antigen presentation for immune response. It also serves as cell surface receptor for the cytokine macrophage migration inhibitory factor (MIF) which, when bound to the encoded protein, initiates survival pathways and cell proliferation. This protein also interacts with amyloid precursor protein (APP) and suppresses the production of amyloid beta (Abeta). Multiple alternatively spliced transcript variants encoding different isoforms have been identified. [provided by RefSeq, Aug 2011]

CD74: 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. A chromosomal aberration involving CD74 is found in a non-small cell lung tumor. Results in the formation of a CD74- ROS1 chimeric protein. 3 isoforms of the human protein are produced by alternative splicing.

Protein type: Membrane protein, integral; Endoplasmic reticulum; Receptor, cytokine

Chromosomal Location of Human Ortholog: 5q32

Cellular Component: lysosomal lumen; cell surface; lysosomal membrane; integral to membrane; MHC class II protein complex; Golgi membrane; multivesicular body; membrane; plasma membrane; vacuole; trans-Golgi network membrane; intracellular; external side of plasma membrane

Molecular Function: hematopoietin/interferon-class (D200-domain) cytokine receptor activity; identical protein binding; protein binding; beta-amyloid binding; cytokine binding; MHC class II protein binding, via antigen binding groove; nitric-oxide synthase binding; MHC class II protein binding

Biological Process: activation of MAPK activity; positive regulation of dendritic cell antigen processing and presentation; antigen processing and presentation of exogenous peptide antigen via MHC class II; defense response; prostaglandin biosynthetic process; signal transduction; negative regulation of T cell differentiation; intracellular protein transport; negative regulation of DNA damage response, signal transduction by p53 class mediator; positive regulation of fibroblast proliferation; negative regulation of mature B cell apoptosis; positive regulation of B cell proliferation; protein complex assembly; positive thymic T cell selection; negative regulation of peptide secretion; positive regulation of T-helper 2 type immune response; chaperone cofactor-dependent protein folding; regulation of macrophage activation; T cell selection; negative thymic T cell selection; cell proliferation; positive regulation of peptidyl-tyrosine phosphorylation; positive regulation of T cell differentiation; immunoglobulin mediated immune response; positive regulation of cytokine and chemokine mediated signaling pathway; antigen processing and presentation of endogenous antigen; negative regulation of apoptosis