A new ERK2 binding protein, Naf1, attenuates the EGF/ERK2 nuclear signaling.
Extracellular signal regulated kinase1/2 (ERK1/2), an important factor in signal transduction, controls cell growth, differentiation, and death. To elucidate the details of the mechanism of ERK1/2 signaling in human cells, we isolated Nef-associated factor 1 alpha (Naf1 alpha) by a yeast two-hybrid system, which bound to human ERK2. The binding was confirmed by a pull-down assay in vitro and immunoprecipitation in vivo. Upon EGF treatment, Naf1 alpha was phosphorylated by the EGF/MEK/ERK2 signal transduction pathway. To identify the role of Naf1 alpha in the ERK2 signaling, Naf1 alpha-expressing Saos-2 cells were analyzed for ERK2 nuclear translocation and activation of its downstream target. Overexpression of Naf1 alpha suppressed ERK2 entering into the nucleus and inhibited the ERK2-dependent Elk1-driven luciferase transcription, suggesting Naf1 alpha to be an attenuator of activated ERK2 signaling.
Zhang
Shengliang
S
Department of Molecular Cellular Oncology, Graduate School, Tokyo Medical and Dental University, Tokyo 113, Japan.
Fukushi
Masaya
M
Hashimoto
Shinichi
S
Gao
Chongfeng
C
Huang
Lin
L
Fukuyo
Yayoi
Y
Nakajima
Takuma
T
Amagasa
Teruo
T
Enomoto
Shoji
S
Koike
Katsuro
K
Miura
Osamu
O
Yamamoto
Naoki
N
Tsuchida
Nobuo
N
D002467:Cell Nucleus / Q000378:metabolism; D002478:Cells, Cultured; D003593:Cytoplasm / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000378:metabolism*; D004815:Epidermal Growth Factor / Q000378:metabolism*; D006801:Humans; D019950:Mitogen-Activated Protein Kinase 1 / Q000378:metabolism* / Q000502:physiology; D048052:Mitogen-Activated Protein Kinase 3; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D010766:Phosphorylation; D015398:Signal Transduction / Q000502:physiology*; D020798:Two-Hybrid System Techniques
D004268:DNA-Binding Proteins; C117046:TNIP1 protein, human; D004815:Epidermal Growth Factor; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D020928:Mitogen-Activated Protein Kinases