Isolation and characterization of Neurospora crassa nucleoside diphosphate kinase NDK-1.
We have previously reported that phosphorylation of a 15-kDa protein increased after blue-light irradiation in Neurospora crassa. In this study, the 15-kDa protein was purified using four columns; DEAE-cellulose, Blue-Sepharose, SP-Sepharose and Mono Q. The 15-kDa protein was shown to be homologous with nucleoside diphosphate kinase by amino acid sequencing and was also shown to possess nucleoside diphosphate kinase activity. A gene encoding N. crassa nucleoside diphosphate kinase, ndk-1, was isolated from the mycelial cDNA and genomic libraries. The deduced amino acid sequence of NDK-1 was identical to that of the 15-kDa protein. Northern blot analysis suggested that WC-1 and WC-2, the key factors of blue-light signal transduction in N. crassa, did not regulate NDK-1 at the transcriptional level. NDK-1 also showed rapid autophosphorylation activity and protein kinase activity against myelin basic protein with a Km value of 0.36 mM. These results suggest that NDK-1 acts as a signal transducer by phosphorylating proteins.
Ogura
Y
Y
Kihara Institute for Biological Reserach, Graduate School of Integrated Science, Yokohoma City University, Japan.
Yoshida
Y
Y
Ichimura
K
K
Aoyagi
C
C
Yabe
N
N
Hasunuma
K
K
D000595:Amino Acid Sequence; D000818:Animals; D003001:Cloning, Molecular; D015971:Gene Expression Regulation, Enzymologic; D015966:Gene Expression Regulation, Fungal; D005800:Genes, Fungal; D006801:Humans; D007700:Kinetics; D008027:Light; D008969:Molecular Sequence Data; D008970:Molecular Weight; D009492:Neurospora crassa / Q000201:enzymology* / Q000235:genetics / Q000528:radiation effects; D009701:Nucleoside-Diphosphate Kinase / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism; D010766:Phosphorylation; D017386:Sequence Homology, Amino Acid; D015398:Signal Transduction
D009701:Nucleoside-Diphosphate Kinase