Career:

Research:

Activation of signaling molecules in neuronal cells

Phosphorylation and dephosphorylation play critical roles in the activation and deactivation of intracellular signaling pathways. We have been studying the activation and phosphorylation of intracellular signaling molecules in rat brain after electroconvulsive shock and also in neuronal cell lines. Previously, we reported the activation MAPK family kinases and other kinases such as CaMK and RSK in rat hippocampus after ECS. Recently, we found that ERM family proteins and a tau kinase, MARK, are also phosphorylated in rat brain and neuronal cell lines. Now we are studying the signaling pathways for the phosphorylation of these proteins and their function in neuronal cells, and also identifying more phosphorylated proteins in rat brain after ECS

Genes up and down regulated in human gastric cancers

Cancer is a disease caused by genetic changes and also transformation induced changes in the expression of various genes. To elucidate the genes involved in the carcinogenesis of stomach cancers, we identified up and down regulated genes in primary human stomach cancers by differential display PCR. Some of the cloned sequences are known genes with known functions, but many of the sequences are from unknown genes. We are interested in the up regulated sequences and were able to clone one of these sequences, CKAP2. The function of CKAP2 is unknown yet, but our results suggested that this protein is related to the cell cycle regulation and expressed in all of the proliferating cells including transformed cells. We are now studying the roles of this new gene, CKAP2, in cell cycle progress by transgenic and knock-out mouse model. We are also trying to clone other sequences which are up regulated in stomach cancers but without known functions.

Publications:

1. Yong Min Ahn, Ung Gu Kang, Seung Wook Oh, Yong-Sung Juhnn, Yeon-Ho Joo, Joo-Bae Park, Yong Sik Kim (2002) Region-specific phosphorylation of ATF-2, Elk-1 and c-Jun in rat hippocampus and cerebellum after electroconvulsive shock. Neuroscience Letters, 329 (1), 9-12
2. Songhee Jeon, Sohee Kim, Jong-Bae Park, Pann-Ghill Suh, Yong Sik Kim, Chang-Dae Bae, Joobae Park (2002) RhoA and Rho-kinase dependent phosphorylation of moesin at Thr-558 in hippocampal neuronal cells by glutamate. Journal of Biological Chemistry, 277 (19), 16576-16584
3. Young Jin Koo, Su-Jin Kim, Song Hee Jeon, Seung Ryul Kim, Ung Gu Kang, Joo-Bae Park, Yong Sik Kim (2002) Electroconvulsive shock increases the phosphorylation of amphiphysin II in the rat cerebellum. Neuroscience Letters, 330 (2), 135-138
4. Bae Chang-Dae, Juhnn Yong-Sung, Park Joo-Bae (2001) Post-transcriptional control of c-erbB2 over-expression in stomach cancer cells. Experimental & Molecular Medicine. 33 (1), 15-19,
5. Song Hee Jeon, Seung Wook Oh, Ung Gu Kang, Yong Min Ahn, Chang-Dae Bae, Joo-Bae Park, Yong Sik Kim (2001) Electroconvulsive shock increases the phosphorylation of Pyk2 in the rat hippocampus. Biochem. Biophys. Res. Comm. 282, 1026-1030
6. Kang Ung Gu, Jeon Song Hee, Lee Jong Eun, Joo Yeon-Ho, Yi Jung Seo, Park Joo-Bae, Juhnn Yong Sung, Kim Yong Sik (2000) The activation of B-Raf and Raf-1 after electroconvulsive shock in the rat hippocampus. Neuropharmacology, 39 (4), 703-706.
7. Youshin Suh, Ung Gu Kang, Yong Sik Kim, Woo-Ho Kim, Sang-Chul Park, Joo-Bae Park (2000) Differential activation of JNK and p38 mitogen-activated protein kinases by methyl methanesulfonate in the liver and brain of rats: Implication in organ-specific carcinogenesis by methyl methanesulfonate. Cancer Research, 60 (18), 5067-5073
8. Ahn Yong Min, Oh Seung Wook, Kang Ung Gu, Park Joo-Bae, Kim Yong Sik (2000) An N-methyl-D-aspartate antagonist, MK-801, preferentially reduces electroconvulsive shock-induced phosphorylation of p38 mitogen-activated protein kinase in the rat hippocampus. Neurosci Letters. 296(2-3), 101-4
9. Oh Seung Wook, Ahn Yong Min, Kang Ung Gu, Kim Yong Sik, Park Joo-Bae (1999) Differential activation of c-Jun N-terminal protein kinase and p38 in rat hippocampus and cerebellum after electroconvulsive shock. Neuroscience Letters, 271, 101-104
10. M. R. Smith, D. W. Court, H. K. Kim, S. G. Rhee, Joo Bae Park, J. S. Rhim, H. Kung (1998) Overexpression of PLC¥ã in NIH 3T3 cells promotes transformation and tumorigenecity. Carcinogenesis, 19 (1), 177-185
11. Jung Hee Yeon, Kang Ung Gu, Joo Yeon Ho, Cho Soo Churl, Jeon Song Hee, Park Joo-Bae, Kim Yong Sik (1998) Electroconvulsive shock does not induce c-fos and jun B, but TIS1 and TIS8/Zif-268, in neonatal rat hippocampus. Developmental Brain Research, 108 (1-2), 303-306,
12. Jeon Song Hee, Yoo Bum Hee, Kang Ung Gu, Ahn Yong Min, Chang-Dae Bae, Joo-Bae Park, Yong Sik Kim (1998) MKP-1 induced in rat brain after electroconvulsive shock is independent of regulation of 42 and 44-kDa MAPK activity. Biochem. Biophys. Research Comm. 249 (3), 692-696
13. Jeon Song Hee, Seong Yeon-Sun, Juhnn Yong-Sung, Kang Ung Gu, Ha Kyoo Seob, Kim Yong Sik, Park Joo-Bae (1997) Electroconvulsive shock increases the phosphorylation of cyclic AMP response element binding protein at Ser-133 in rat hippocampus but not in cerebellum. Neuropharmacology, 36 (3), 411-414
14. Jung, H. Y., Kang U. G., Ahn, Y, M., Joo, Y. H., Park, J-B., Kim, Y. S. : Induction of tetradecanoyl phorbol acetate-inducible sequence (TIS) genes by electroconvulsive shock in rat brain. Biological Psychiatry, 40, 503-507, 1996
15. Bae, C-D., Lee, T-H., Park, J-B. : Quantitation of c-erbB-2 mRNA by competitive reverse transcriptase-polymerase chain reaction. Mol. Cells, 6 (1) 101-107, 1996
16. Joh, J-W., Noh, D-Y., Bae, C-D., Choe, K-J., Park, J-B. : Amplification and over-expression of erbB-2 oncogene in primary human breast tumors. Experimental and Molecular Medicine, 28 (1), 47-53, 1996
17. Shin, C. J., Kim, Y.S., Park, J-B., Juhnn, Y-S. : Changes in G proteins in the hippocampus and the striatum of rat brain after chronic treatment with haloperidol and sulpride. Neuropharmacology, 34 (10), 1335-1338, 1995
18. Kim, Y. S., Hong, K. S., Seong, Y-S., Park, J-B., Kuroda, S., Kishi, K., Kaibuchi, K., Takai, Y. : Phosphorylation and activation of mitogen-activated protein kinase by kainic-acid induced seizure in rat hippocampus. Biochem. Biophys. Res. Commun. 202, 1163-1168, 1994
19. Kang, U. G., Hong, K. S., Jung, H. Y., Kim, Y. S., Seong, Y-S., Yang Y. C., Park, J-B. : Activation and tyrosine phosphorylation of 44-kDa mitogen-activated protein kinase (MAPK) induced by electroconvulsive shock in rat hippocampus. J. of Neurochemistry, 63 (5), 1979-1982, 1994
20. Kim H., Ko J. P., Kang U. G., Park J-B., Kim H-L., Kim Y. S. : Electroconvulsive shock reduces inositol 1,4,5-triphosphate 3-kinase mRNA expression in rat dentate gyrus. J. of Neurochemistry, 63 (5), 1991-1994, 1994