Cloning, expression and characterisation of a human Nudix hydrolase specific for adenosine 5'-diphosphoribose (ADP-ribose).
The human NUDT9 gene has been mapped to 4q22 and shown to give rise to two alternatively spliced mRNAs, NUDT9alpha and NUDT9beta, that encode a member of the Nudix hydrolase family. Both transcripts were readily detected in heart and skeletal muscle and also in liver, kidney and pancreas. NUDT9alpha protein was expressed in Escherichia coli and shown specifically to hydrolyse ADP-ribose and IDP-ribose to the corresponding nucleoside 5'-monophosphates and ribose 5-phosphate. No other nucleotide substrates were hydrolysed significantly. NUDT9alpha was inhibited by fluoride and by N-acetyl-p-benzoquinoneimine and had K(m) and kcat values of 180 microM and 8 s(-1) respectively with ADP-ribose as substrate. The full-length 39.1 kDa NUDT9alpha has a potential mitochondrial leader sequence, which would give rise to a mature 34.2 kDa mitochondrial protein. Apart from the high K(m) value, the properties of NUDT9alpha are close to those of the known mammalian 40 kDa cytoplasmic ADPRibase-1 and 35 kDa mitochondrial ADPRibase-m. However, any relationship between the NUDT9 species and the previously reported ADPRibases remains to be established.
Lin
Shengrong
S
State Key Laboratory of Genetic Engineering, Institute of Genetics, School of Life Science, Fudan University, Shanghai 200433, PR China.
Gasmi
Lakhdar
L
Xie
Yi
Y
Ying
Kang
K
Gu
Shaohua
S
Wang
Zhao
Z
Jin
Hua
H
Chao
Yueqiong
Y
Wu
Chaoqun
C
Zhou
Zongxiang
Z
Tang
Rong
R
Mao
Yumin
Y
McLennan
Alexander G
AG
D000246:Adenosine Diphosphate Ribose / Q000378:metabolism*; D017398:Alternative Splicing; D000595:Amino Acid Sequence; D001483:Base Sequence; D002413:Cations, Divalent; D002874:Chromosome Mapping; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000096:biosynthesis / Q000737:chemistry; D004926:Escherichia coli / Q000378:metabolism; D006801:Humans; D007700:Kinetics; D008274:Magnesium; D008345:Manganese; D008969:Molecular Sequence Data; D018482:Muscle, Skeletal / Q000201:enzymology; D009206:Myocardium / Q000201:enzymology; D011755:Pyrophosphatases / Q000096:biosynthesis / Q000737:chemistry / Q000235:genetics*; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D013379:Substrate Specificity; D000096964:Nudix Hydrolases
D000246:Adenosine Diphosphate Ribose; D002413:Cations, Divalent; D018076:DNA, Complementary; D008274:Magnesium; D008345:Manganese; D011755:Pyrophosphatases; D000096964:Nudix Hydrolases