Ectonucleoside triphosphate diphosphohydrolase-1 (gene: ENTPD1; protein: NTPDase1) also known as CD39 (Cluster of Differentiation 39), is a typical cell surface enzyme with a catalytic site on the extracellular face.[5][6][7]
Function
NTPDase1 is an ectonucleotidase that catalyse the hydrolysis of γ- and β-phosphate residues of triphospho- and diphosphonucleosides to the monophosphonucleoside derivative.[8][9] NTPDase1 hydrolyzes P2 receptor ligands, namely ATP, ADP, UTP and UDP with similar efficacy.[10] NTPDase1 can therefore affect P2 receptor activation and functions.[11]
Clinical significance
ATP causes a pro-inflammatory environment, whereas degradation of ATP into adenosine by the CD39/CD73 pathway leads to an anti-inflammatory environment.[12] CD39 converts ATP (or ADP) to adenosine monophosphate (AMP), which is converted into adenosine by CD73.[12][13] A substantial portion of the immune suppressive and anti-inflammatory activity of regulatory T cells (Tregs) is due to the adenosine produced by the CD39/CD73 pathway, insofar as Tregs express CD39 and CD73.[12][13]
Adenosine produced by the CD39/CD73 pathway can protect against ischemia-reperfusion injury.[12] On the other hand, high expression and activity of CD39 and CD73 on cancer cells can prevent the immune system from inhibiting the progression of cancer.[12]
Biallelic pathogenic variant in ENTPD1 causes autosomal recessive spastic paraplegia 64 (SPG64).[14][15] SPG64 is a complex hereditary spastic paraplegia characterized by childhood onset progressive spastic paraparesis, delayed developmental milestones, intellectual disability, dysarthria, and white matter abnormalities.
See also
References
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