| Modification Notes |
Sialin, also designated sodium/sialic acid cotransporter or membrane glycoprotein HP59, belongs to the major facilitator superfamily and the sodium/anion cotransporter family of proteins. Sialin acts as a solute translocator for anionic substances; in lysosomes it is a free sialic acid transporter. Sialin is a multi-pass membrane protein that localizes to the lysosome and is primarily detected in fetal lung and small intestine. It is also expressed in adult placenta, kidney and pancreas, and may be detected in colon, breast and ovary tumor endothelial cells as well. Defects in the SLC17A5 gene, which encodes the Sialin protein, can cause several disorders including Salla disease, an autosomal recessive sialic acid storage disease, as well as infantile sialic acid storage disorder (ISSD), a severe form of sialic acid storage disease in which affected newborns exhibit coarse features, visceromegaly (an enlargement of the internal organs) and a failure to thrive after birth. |