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.,similarity:Contains 1 thyroglobulin type-1 domain.,subunit:Nonamer composed of three alpha/beta/gamma heterotrimers.,
Cell membrane ; Single-pass type II membrane protein . Endoplasmic reticulum membrane. Golgi apparatus, trans-Golgi network. Endosome. Lysosome. 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 .
[Isoform p41]: In B cells, represents 10% of total CD74 expression. ; [Isoform p33]: In B cells, represents 70% of total CD74 expression.