Urea transporter (IPR004937)

Short name: Urea_transporter

Overlapping homologous superfamilies

Family relationships


Proteins in this entry include low-affinity urea transporters found in the erythrocytes and kidneys of higher organisms. The erythrocyte proteins carry the clinically important Kidd (Jk) blood group antigens which help determine blood type. The two commonest forms are Jk(a) and Jk(b), which arise from a single residue variation at position 280; aspartate in Jk(a) and asparagine in Jk(b) [PMID: 9215669]. A much rarer phenotype, Jk(null), arises when the protein is not expressed on the erythrocyte surface, and is linked to a urine-concentrating defect [PMID: 1498276]. The Kidd blood group is clinically significant as Jk antibodies can cause acute transfusion reactions and haemolytic disease of the newborn (HDN), where the mother's body creates antibodies against the foetal blood cells. HDN associated with Jk antibodies is generally mild, but fatal cases can occur [PMID: 16479082].

The bacterial proteins in this entry also appear to be involved in urea transport, promoting its entry into the cell [PMID: 12180933]. This uptake of urea can be advantageous for bacteria as its hydrolysis by urease generates ammonium which is an efficient source of nitrogen and, through its buffering capacity, can also provide resistance to acidic conditions.

GO terms

Biological Process

GO:0071918 urea transmembrane transport

Molecular Function

GO:0015204 urea transmembrane transporter activity

Cellular Component

GO:0016021 integral component of membrane

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.