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Junn, Eunsung PhD

Assistant Professor
Ph.D. Korea Advanced Institute of Science and Technology (KAIST), 1996

Phone: 732-235-5478 (office) 732-235-5477 (lab)
Fax: 732-235-4773

Research Interest

My research employs genetic, cell biological and biochemical approaches to explore the pathogenesis of Parkinson’s disease (PD).PD is a common disorder of the nervous system that affects patients later in life with tremor, slowness of movements, gait instability, and rigidity.These impairments stem from the progressive loss of dopaminergic neurons in the midbrain. Although the majority of Parkinson cases appear to be sporadic, the disorder runs in families in about 15-20% of the cases. Mutations in at least five genes including a-synuclein, parkin, pink1, dj-1 and lrrk2 are responsible for rare familial forms of PD. Understanding how mutations in these genes cause neurodegeneration is crucial in the development of new treatments that might slow or stop the disease progression. Consequently, investigating the role of these genes in the pathogenesis of PD has become one of my research projects.

MicroRNAs (miRNAs) are a class of endogenous 20-25 base-long single-stranded, non-coding RNAs that negatively regulate gene expression in a sequence-specific manner by binding to their target sequence in the 3’ untranslated region (UTR) of mRNA. Recently, we showed that microRNA-7 (miR-7), which is expressed mainly in neurons, represses a-Synuclein protein levels through the 3’-untranslated region (UTR) of a-Syn mRNA. Importantly, miR-7-induced down-regulation of a-Synuclein expression protects cells against oxidative stress. Currently, my research extends these findings including testing the effects of miRNAs in in vivo mouse models. Identifying miRNA species involved in the pathogenesis of PD is one of my active research interests.

Selected Publications

  • Junn E, Han SH, Im JY, Cho EW, Um HD, Kim DK, Lee KW, Han PL, Rhee SG and Choi I “Vitamin D3 Up-Regulated Protein 1 Mediates Oxidative Stress Via Suppressing the Thioredoxin Function” J. Immunol. 164(12):6287-6295, 2000.
  • Junn E, Lee KN, Ju HR, Han SH, Im JY, Kang HS, Lee TH, Bae YS, Ha KS, Lee ZW, Rhee SG, and Choi I,“Requirement of Hydrogen Peroxide Generation in TGF-beta1 Signal Transduction in Human Lung Fibroblast Cells: Involvement of Hydrogen Peroxide and Ca2+ in TGF-beta1-Induced IL-6 Expression.” J Immunol. 165(4):2190-2197, 2000.
  • Waragai M, Junn E, Kajikawa M, Takeuchi S, Kanazawa I, Shibata M, Mouradian MM, Okazawa H “PQBP-1/Npw38, a nuclear protein binding to the polyglutamine tract, interacts with U5-15kD/dim1p via the carboxyl-terminal domain.” Biochem Biophys Res Commun. 273(2):592-5, 2000. (Co-First Author)
  • Yang Y, Hwang CK, D'Souza UM, Lee SH, Junn E, and Mouradian MM “Three-amino Extension Loop Homeodomain Proteins Meis2 and TGIF Differentially Regulate Transcription” J. Biol. Chem. 275(27):20734-2074, 2000.
  • Yang Y, Hwang CK, Junn E, Lee G, and Mouradian MM, “ZIC2 and Sp3 Repress Sp1-Induced Activation of the Human D1A Dopamine Receptor Gene” J. Biol. Chem., 275(49): 38863-38869, 2000.
  • D’Souza UM, Wang W, Gao DQ, Kanda S, Lee G, Junn E, Hwang CK, Jose PA, and Mouradian MM “ Characterization of the 5’ flanking region of the rat D3 dopamine receptor gene” J. Neurochem. 76(6): 1736-1744, 2001.
  • Junn E and Mouradian MM “Apoptotic signaling in Dopamine-induced Cell Death: The Role of Oxidative Stress, p38 Mitogen-Activated Protein Kinase, Cytochrome c and Caspases” J. Neurochem., 78(2): 374-383, 2001.
  • Junn E and Mouradian MM “Human a-Synuclein over-expression increases intracellular reactive oxygen species levels and susceptibility to dopamine” Neuroscience Lett. 320: 146-150, 2002.
  • Lee G, Junn E, Tanaka M, Kim YM, Lee SS, and Mouradian MM “ Synphilin-1 degradation by the ubiquitin-proteasome pathway and effects on cell survival” J. Neurochem., 83(2): 346-352, 2002 (Co-First Author).
  • Junn E, Lee SS, Suhr UT and Mouradian MM “Parkin Accumulation in Aggresomes due to Proteasome impairment” J. Biol. Chem., 277(49): 47870-47877, 2002.
  • Junn E, Ronchetti RD, Quezado MM, Kim SY, Mouradian MM. “Tissue transglutaminase- induced aggregation of {alpha}-synuclein: Implications for Lewy body formation in Parkinson's disease and dementia with Lewy bodies.” Proc Natl Acad Sci U S A, 100(4): 2047-2052, 2003.
  • Lee SS, Kim YM, Junn E, Lee G, Park KH, Tanaka M, Ronchetti RD, Quezado MM, Mouradian MM “ Cell cycle aberration by a-Synuclein over-expression and cyclin B immunoreactivity in Lewy bodies”, Neurobiology of Aging, 24(5): 687-696, 2003.
  • Tanaka M, Kim YM, Lee G, Junn E, Iwatsubo T and Mouradian MM “Aggresomes formed by a-Synuclein and Synphilin-1 are cytoprotective”, J. Biol. Chem,. 279(6): 4625-4631, 2004.
  • Lee G, Tanaka M, Park K, Lee SS, Kim YM, Junn E Lee SH and Mouradian MM “Casein kinase II phosphorylation regulates Synphilin-1/a-Synuclein interaction and inclusion body formation” J. Biol. Chem., 279(8): 6834-6839. 2004.
  • Junn E, Taniguchi H, Jeong BS, Zhao X, Ichijo H and Mouradian MM “ Interaction of DJ-1 with Daxx inhibits apoptosis signal-regulating kinase activity and cell death” Proc. Natl. Acad. Sci. USA. 102(27): 9691-9696. 2005.
  • Park KA, Byun HS, Won M, Yang KJ, Shin S, Piao L, Kim JM, Woon WH, Junn E, Park J, Seok JH, Hur GM. “Sustained activation of protein kinase C down-regulates nuclear factor-{kappa}B signaling by dissociation of IKK-{gamma} and Hsp90 complex in human colonic epithelial cells.” Carcinogenesis 28(1): 71-80. 2007.
  • Junn E, Jang WH, Zhao X, Jeong BS and Mouradian MM “Mitochondrial Localization of DJ-1 Leads to Enhanced Neuroprotection” J. Neurosci. Res. 87(1): 123-129. 2009.
  • Junn E, Lee KW, Jeong BS, Chan TW, Im JW and Mouradian MM “Repression of alpha-synuclein expression and toxicity by microRNA-7” Proc. Natl. Acad. Sci. USA. 106(31):13052-7. 2009. (Corresponding author)
  • Junn E and Mouradian MM “ MicroRNAs in Neurodegenerative disorders” Cell Cycle, May 25;9(9). 2010. (Corresponding author)
  • Im JY, Lee KW, Junn E and Mouradian MM “DJ-1 Protects Against Oxidative Damage by Regulating the Thioredoxin/ASK1 Complex” Neuroscience Res. 2010 April 10 (Epub ahead of print) PMID 20385180.
  • Lee EJ, Woo MS, Moon PG, Baek MC, Choi IY, Kim WK, Junn E and Kim HSa-Synuclein Activates Microglia by Inducing the Expressions of Matrix Metalloproteinases and the Subsequent Activation of Protease-Activated Receptor-1” J. Immunol. 2010 May 28 (Epub ahead of print) PMID: 20511551.