ENTPD5
Description
The ENTPD5 (ectonucleoside triphosphate diphosphohydrolase 5 (inactive)) is a protein-coding gene located on chromosome 14.
ENTPD5, encoded by the ENTPD5 gene, is an enzyme similar to E-type nucleotidases (NTPases)/ecto-ATPase/apyrases. These enzymes, such as CD39, are involved in the breakdown of extracellular nucleotides. ENTPD5 contains four apyrase-conserved regions, a characteristic of NTPases.
ENTPD5 hydrolyzes nucleoside diphosphates, favoring GDP, IDP, and UDP over ADP and CDP. Within the endoplasmic reticulum (ER) lumen, ENTPD5 breaks down UDP, which acts as a feedback inhibitor of UDP-Glc:glycoprotein glucosyltransferases. UMP is transported back to the cytosol by an UDP-sugar antiporter, where it is used to regenerate UDP-glucose. This process positively regulates protein reglucosylation by clearing UDP from the ER lumen and promoting UDP-glucose synthesis. Protein reglucosylation is crucial for proper glycoprotein folding and quality control within the ER.
ENTPD5 is also known as CD39L4, NTPDase-5, PCPH.
Associated Diseases
- familial steroid-resistant nephrotic syndrome with sensorineural deafness
- progressive familial intrahepatic cholestasis
- neonatal intrahepatic cholestasis due to citrin deficiency
- glycogen storage disease VI
- glycogen storage disease due to liver phosphorylase kinase deficiency
- citrullinemia type II
