| Modification Notes |
The Kidd antigen system (also referred to as the Jk antigen system) exists on the membrane of red blood cells (erythrocytes) and is responsible for urea transport and blood type determination. On the surface of red blood cells, Jk antigens (which exist as two alleles, designated Jk(a) and Jk(b)) are associated with a protein, known as UT-B, whose function is to mediate urea transport in kidneys and erythrocytes. UT-B, also known as SLC14A (solute carrier family 14 (urea transporter), member 1 (Kidd blood group)), Jk, UT1, UTE, HUT11 or RACH1, is a 389 amino acid multi-pass membrane protein that is exists as a low-affinity urea transporter and is responsible for determination of Jk alleles. The gene encoding UT-B maps to human chromosome 18, which houses over 300 protein-coding genes and contains nearly 76 million bases. |