Isolation and characterization of a Drosophila homologue of mitogen-activated protein kinase phosphatase-3 which has a high substrate specificity towards extracellular-signal-regulated kinase.
A partial C-terminal cDNA sequence of a novel Drosophila mitogen-activated protein kinase phosphatase (MKP), designated DMKP-3, was identified from an epitope expressed sequence tag database, and the missing N-terminal cDNA fragment was cloned from a Drosophila cDNA library. DMKP-3 is a protein of 411 amino acids, with a calculated molecular mass of 45.8 kDa; the deduced amino acid sequence is most similar to that of mammalian MKP-3. Recombinant DMKP-3 produced in Escherichia coli retained intrinsic tyrosine phosphatase activity. In addition, DMKP-3 specifically inhibited extracellular-signal-regulated kinase (ERK) activity, but was without a significant affect on c-Jun N-terminal kinase (JNK) and p38 activities, when it was overexpressed in Schneider cells. DMKP-3 interacted specifically with Drosophila ERK (DERK) via its N-terminal domain. In addition, DMKP-3 specifically inhibited Elk-1-dependent trans-reporter gene expression in mammalian CV1 cells, and dephosphorylated activated mammalian ERK in vitro. DMKP-3 is uniquely localized in the cytoplasm within Schneider cells, and gene expression is tightly regulated during development. Thus DMKP-3 is a Drosophila homologue of mammalian MKP-3, and may play important roles in the regulation of various developmental processes.
Kim
Sun-Hong
SH
Department of Biochemistry and Molecular Biology, Institute of Genetic Science, Yonsei University College of Medicine, Seoul 120-752, South Korea.
Kwon
Hyung-Bae
HB
Kim
Yong-Sik
YS
Ryu
Ji-Hwan
JH
Kim
Kyung-Sub
KS
Ahn
Yongho
Y
Lee
Won-Jae
WJ
Choi
Kang-Yell
KY
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D003001:Cloning, Molecular; D003593:Cytoplasm / Q000201:enzymology; D018076:DNA, Complementary / Q000235:genetics; D004330:Drosophila / Q000201:enzymology* / Q000235:genetics; D054642:Dual Specificity Phosphatase 6; D004926:Escherichia coli / Q000235:genetics; D006801:Humans; D066298:In Vitro Techniques; D048031:JNK Mitogen-Activated Protein Kinases; D008322:Mammals; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism*; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D017434:Protein Structure, Tertiary; D017027:Protein Tyrosine Phosphatases / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D013045:Species Specificity; D013379:Substrate Specificity; D048051:p38 Mitogen-Activated Protein Kinases
D018076:DNA, Complementary; D012333:RNA, Messenger; D011994:Recombinant Proteins; D048031:JNK Mitogen-Activated Protein Kinases; D020928:Mitogen-Activated Protein Kinases; D048051:p38 Mitogen-Activated Protein Kinases; C517035:DUSP6 protein, human; D054642:Dual Specificity Phosphatase 6; D017027:Protein Tyrosine Phosphatases