Human erythrocyte pyrimidine 5-nucleotidase, PN-I, is identical to p36, a protein associated to lupus inclusion formation in response to alpha-interferon.
Erythrocyte maturation is accompanied by RNA degradation and release of mononucleotides. We have previously purified PN-I, a pyrimidine nucleotidase whose deficiency is associated with hemolytic anemia. Computer-aided analysis of PN-I tryptic and CNBr peptide sequences revealed substantial identity with tryptic peptide sequences reported for p36, an alpha-interferon-induced protein. PN-I partial sequences were matched through the expressed sequence tag database with different human complementary DNA (cDNA) clones, whose sequences were exploited to screen a human placenta cDNA library. PN-I cDNA, coding for a 286-residue protein, was expressed in Escherichia coli, yielding a fully active recombinant enzyme. The recombinant protein sequence comprised the peptide sequences determined for PN-I and p36. Rabbit antisera raised against two peptides deriving from p36 and PN-I tryptic digestions, respectively, recognized both wild-type and recombinant PN-I. Molecular properties of the two proteins were essentially the same. We conclude that p36 and PN-I are identical proteins. (Blood. 2000;96:1596-1598)
Amici
A
A
Istituto di Biochimica and Dipartimento di Biotecnologie Agrarie ed Ambientali, Università di Ancona, Ancona, Italy.
Emanuelli
M
M
Raffaelli
N
N
Ruggieri
S
S
Saccucci
F
F
Magni
G
G
D015720:5'-Nucleotidase / Q000032:analysis / Q000235:genetics* / Q000378:metabolism; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D001798:Blood Proteins / Q000032:analysis / Q000235:genetics*; D018076:DNA, Complementary / Q000032:analysis / Q000235:genetics; D004912:Erythrocytes / Q000201:enzymology*; D006023:Glycoproteins / Q000032:analysis / Q000235:genetics*; D006801:Humans; D016898:Interferon-alpha / Q000494:pharmacology*; D008969:Molecular Sequence Data; D011817:Rabbits; D016415:Sequence Alignment; D017385:Sequence Homology
D001798:Blood Proteins; D018076:DNA, Complementary; D006023:Glycoproteins; D016898:Interferon-alpha; D015720:5'-Nucleotidase; C412794:NT5C3A protein, human