CD320 Antigen (CD320) Human Recombinant Protein

This gene encodes the transcobalamin receptor that is expressed at the cell surface. It mediates the cellular uptake of transcobalamin bound cobalamin (vitamin B12), and is involved in B-cell proliferation and immunoglobulin secretion. Mutations in this gene are associated with methylmalonic aciduria. Alternatively spliced transcript variants encoding different isoforms have been found for this gene.[provided by RefSeq, Jan 2011]

CD320: Germinal center-B (GC-B) cells differentiate into memory B-cells and plasma cells (PC) through interaction with T-cells and follicular dendritic cells (FDC). CD320 augments the proliferation of PC precursors generated by IL-10. Receptor for the cellular uptake of transcobalamin bound cobalamin. Defects in CD320 are the cause of methylmalonic aciduria type TCblR (MMATC); also called methylmalonic aciduria due to transcobalamin receptor defect. MMATC is a metabolic disorder characterized by increased blood C3- acylcarnitine levels, elevated methylmalonate and homocysteine, and low uptake of transcobalamin-bound cobalamin, but normal conversion to adenosylcobalamin and methylcobalamin. Plasma vitamin B12 and total homocysteine are normal.

Protein type: Membrane protein, integral

Chromosomal Location of Human Ortholog: 19p13.3-p13.2

Cellular Component: endoplasmic reticulum; endosome membrane; integral to membrane; membrane; plasma membrane

Molecular Function: cobalamin binding; growth factor activity

Biological Process: cobalamin metabolic process; regulation of cell growth; regulation of vitamin metabolic process; vitamin metabolic process; water-soluble vitamin metabolic process

Disease: Methylmalonic Aciduria Due To Transcobalamin Receptor Defect