Cobalamin-transporting protein (Cbl transporter)

Cobalamin-transporting proteins and enzymes encompass a specialized group of proteins and receptors required for the absorption, transport, and cellular utilization of vitamin B12 (cobalamin)[1][2][4][5]. In mammals, three central proteins—haptocorrin, intrinsic factor, and transcobalamin—bind and shuttle cobalamin through various compartments: from dietary uptake in the intestine (mediated by intrinsic factor and the cubilin receptor)[4], to plasma transport (haptocorrin and transcobalamin)[1], and finally, to cellular uptake and delivery to B12-dependent enzymes (methionine synthase and methylmalonyl-CoA mutase)[2][3][5]. Dysfunction or genetic defects in any step may lead to vitamin B12 deficiency, manifesting as anemia or neurological disorders[4][5]. These proteins, particularly transcobalamin and its receptor, are being explored as targets for drug delivery and diagnostic markers[1]. The group is structurally diverse but linked by their essential role in facilitating B12 utilization in cellular metabolism and health[1][2][3][4][5].

Other names

Vitamin B12-binding proteinsCbl transportershaptocorrin (HC)intrinsic factor (IF)transcobalamin (TC)TC IITC II receptorcubilin receptorCbl-binding proteins

Replacement or supplementation of dietary vitamin B12 in deficiency; Delivery of cobalamin via conjugated molecules for receptor-mediated uptake[1]