TY - JOUR
T1 - Drosophila mixed lineage kinase/slipper, a missing biochemical link in Drosophila JNK signaling
AU - Sathyanarayana, Pradeep
AU - Barthwal, Manoj K.
AU - Lane, Mary Ellen
AU - Acevedo, Summer F.
AU - Skoulakis, Efthimios M C
AU - Bergmann, Andreas
AU - Rana, Ajay
N1 - Funding Information:
We thank Dr. Guri Tzivion (Texas A&M University Health Science Center) for providing Raf-1 and MEK1 proteins and the Berkeley Drosophila Genome Project for providing LD library. We are also thankful to Tony Ip (U Mass Medical Center) for providing dMKK4 and Hep plasmid vectors. This work was supported in part by National Institute of Health grant GM55835 to AR. AB is supported by The Welch Foundation.
PY - 2003/4/7
Y1 - 2003/4/7
N2 - Mixed lineage kinases (MLKs) belong to the family of mitogen activated protein kinase kinase kinase (MAPKKK) and cause neuronal cell death mediated through c-Jun, N-terminal kinase (JNK) pathway. Recently, genetic studies in Drosophila revealed the presence of an MLK termed slipper (slpr). However, its biochemical features like physiological substrate, role in different MAPK pathways and developmental and tissue-specific expression pattern were not reported. Here, we report cDNA cloning, expression analysis and biochemical characterization of a Drosophila mixed lineage kinase (dMLK) that is also known as slipper. The protein structure analysis of dMLK/slipper revealed, in addition to the conserved domains, a stretch of glutamine in the amino terminus and an asparagine-threonine stretch at the carboxy-terminus. In situ hybridization and reverse transcriptase polymerase chain reaction (RT-PCR) analysis revealed that dMLK is expressed in early embryonic stages, adult brain and thorax. Ectopic expression of dMLK either in Drosophila S2 or in mammalian HEK293 cells leads to activation of JNK, p38 and extracellular signal regulated kinase (ERK) pathways. Further, dMLK directly phosphorylates Hep, dMKK4 and also their mammalian counterparts, MKK7 and SEK1, in an in vitro kinase assay. Taken together, our results provide for the first time a comprehensive expression profile and new biochemical insight of dMLK/slipper.
AB - Mixed lineage kinases (MLKs) belong to the family of mitogen activated protein kinase kinase kinase (MAPKKK) and cause neuronal cell death mediated through c-Jun, N-terminal kinase (JNK) pathway. Recently, genetic studies in Drosophila revealed the presence of an MLK termed slipper (slpr). However, its biochemical features like physiological substrate, role in different MAPK pathways and developmental and tissue-specific expression pattern were not reported. Here, we report cDNA cloning, expression analysis and biochemical characterization of a Drosophila mixed lineage kinase (dMLK) that is also known as slipper. The protein structure analysis of dMLK/slipper revealed, in addition to the conserved domains, a stretch of glutamine in the amino terminus and an asparagine-threonine stretch at the carboxy-terminus. In situ hybridization and reverse transcriptase polymerase chain reaction (RT-PCR) analysis revealed that dMLK is expressed in early embryonic stages, adult brain and thorax. Ectopic expression of dMLK either in Drosophila S2 or in mammalian HEK293 cells leads to activation of JNK, p38 and extracellular signal regulated kinase (ERK) pathways. Further, dMLK directly phosphorylates Hep, dMKK4 and also their mammalian counterparts, MKK7 and SEK1, in an in vitro kinase assay. Taken together, our results provide for the first time a comprehensive expression profile and new biochemical insight of dMLK/slipper.
KW - Hep
KW - MLK
KW - Slipper
KW - dJNK
KW - dMKK4
KW - dMLK
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U2 - 10.1016/S0167-4889(03)00022-3
DO - 10.1016/S0167-4889(03)00022-3
M3 - Article
C2 - 12676357
AN - SCOPUS:0037424904
SN - 0167-4889
VL - 1640
SP - 77
EP - 84
JO - Biochimica et Biophysica Acta - Molecular Cell Research
JF - Biochimica et Biophysica Acta - Molecular Cell Research
IS - 1
ER -