Molecular cloning of multiple splicing variants of JIP-1 preferentially expressed in brain.
Stress-activated protein kinase/c-Jun N-terminal kinase (SAPK/JNK) is activated by a variety of cellular or environmental stresses. Proper regulation of the SAPK/JNK pathway may be critical for cell survival or death under various conditions. In this study, we report the molecular cloning of novel isoforms of JIP-1, which harbor a putative phosphotyrosine interaction domain and a helix-loop-helix domain, as well as an SH3 homologous region in the C terminus. Northern analysis indicates that transcription variant jip-1 is expressed in brain and kidney and transcription variants jip-2 and jip-3 are specifically expressed in brain. In situ hybridization data showed that the hybridized jip messages were heavily concentrated in adult brain, and were particularly enriched in the cerebral cortex and hippocampus, the brain regions vulnerable to pathological states such as hypoxia-ischemia, epilepsy, and Alzheimer's disease. All the deduced protein products of the jip transcription variants appear to have a similar property in that they inhibit the SAPK/JNK stimulation when overexpressed. Inhibition of SAPK activation by overexpression of the novel isoform JIP-2a resulted in suppression of etoposide-induced cell death in a neuroglioma cell line, N18TG. These findings suggest that JIP may play an important role in regulation of the SAPK pathway that is involved in stress-induced cellular responses.
Kim
I J
IJ
Laboratory for Basic Research, Hanhyo Institutes of Technology, Taejon, Korea.
Lee
K W
KW
Park
B Y
BY
Lee
J K
JK
Park
J
J
Choi
I Y
IY
Eom
S J
SJ
Chang
T S
TS
Kim
M J
MJ
Yeom
Y I
YI
Chang
S K
SK
Lee
Y D
YD
Choi
E J
EJ
Han
P L
PL
D048868:Adaptor Proteins, Signal Transducing; D017398:Alternative Splicing / Q000502:physiology*; D000818:Animals; D017209:Apoptosis / Q000235:genetics; D001921:Brain / Q000166:cytology / Q000201:enzymology; D001923:Brain Chemistry / Q000502:physiology*; D002352:Carrier Proteins / Q000235:genetics*; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000302:isolation & purification; D015971:Gene Expression Regulation, Enzymologic; D015723:Gene Library; D048031:JNK Mitogen-Activated Protein Kinases; D048670:MAP Kinase Kinase 4; D051379:Mice; D008807:Mice, Inbred BALB C; D020929:Mitogen-Activated Protein Kinase Kinases; D008969:Molecular Sequence Data; D009474:Neurons / Q000166:cytology / Q000201:enzymology; D011494:Protein Kinases / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D015398:Signal Transduction / Q000502:physiology; D014158:Transcription, Genetic / Q000502:physiology
D048868:Adaptor Proteins, Signal Transducing; D002352:Carrier Proteins; D018076:DNA, Complementary; C490665:Mapk8ip protein, mouse; D011494:Protein Kinases; D048031:JNK Mitogen-Activated Protein Kinases; D048670:MAP Kinase Kinase 4; D020929:Mitogen-Activated Protein Kinase Kinases