NT5E

Description

The NT5E (5'-nucleotidase ecto) is a protein-coding gene located on chromosome 6.

5'-nucleotidase (5'-NT), also known as ecto-5'-nucleotidase or CD73 (cluster of differentiation 73), is an enzyme that in humans is encoded by the NT5E gene. CD73 commonly serves to convert AMP to adenosine. NT5E contains binding sites for transcription factors AP-2, SMAD proteins, SP-1 and elements responsive to c-AMP, which can be found in c-AMP promoter parts. SMADs 2, 3, 4 and 5 and SP-1 are binding to the NT5E promoter in rats, as was proven in chromatin immunoprecipitation assays. Due to the fact, that the human and rat NT5E transcripts are 89% identical, human NT5E could be also regulated by SMAD proteins. Ecto-5-prime-nucleotidase (5-prime-ribonucleotide phosphohydrolase; EC 3.1.3.5) catalyzes the conversion at neutral pH of purine 5-prime mononucleotides to nucleosides, the preferred substrate being AMP. The enzyme consists of a dimer of 2 identical 70-kD subunits bound by a glycosyl phosphatidyl inositol linkage to the external face of the plasma membrane. The enzyme is used as a marker of lymphocyte differentiation. Consequently, a deficiency of NT5 occurs in a variety of immunodeficiency diseases (e.g., see MIM 102700, MIM 300300). Other forms of 5-prime nucleotidase exist in the cytoplasm and lysosomes and can be distinguished from ecto-NT5 by their substrate affinities, requirement for divalent magnesium ion, activation by ATP, and inhibition by inorganic phosphate. Rare allelic variants are associated with a syndrome of adult-onset calcification of joints and arteries (CALJA) affecting the iliac, femoral, and tibial arteries reducing circulation in the legs and the joints of the hands and feet causing pain.

Catalyzes the hydrolysis of nucleotide monophosphates, releasing inorganic phosphate and the corresponding nucleoside. AMP is the preferred substrate. Ribonucleotide monophosphates are preferred over deoxyribose forms. Other substrates include IMP, UMP, GMP, CMP, dAMP, dCMP, dTMP, NAD and NMN.

NT5E is also known as CALJA, CD73, E5NT, NT, NT5, NTE, eN, eNT.

Associated Diseases

• Hereditary arterial and articular multiple calcification syndrome
• Calcification of joints and arteries