Possible involvement of the expression and phosphorylation of N-Myc in the induction of HMGA1a by hypoxia in the human neuroblastoma cell line.
Increased expression of N-Myc and expression of the high mobility group protein A1a (HMGA1a) were observed in the nuclei of SK-N-SH cells following exposure to hypoxia. These observations were accompanied by the appearance of additional high molecular weight bands, which were eliminated by pretreatment with alkaline phosphatase. Immunoprecipitation showed phosphorylation of serine, threonine and tyrosine residues of N-Myc in the nucleus. These results suggest that hypoxia-induced signals in SK-N-SH cells lead to persistent expression of HMGA1a, which may induce expression of the transcription factor N-Myc, and that phosphorylation at serine, threonine and tyrosine residues of N-Myc occurs at an early stage after stimulation. Such signal consolidation processes could play a role in neuronal survival after hypoxia in neurons.
Yanagita
Takeshi
T
Department of Anatomy and Neuroscience, Graduate School of Medicine, Osaka University, 2-2 Yamadaoka, Suita, Osaka, Japan.
Manabe
Takayuki
T
Okuda
Hiroaki
H
Matsuzaki
Shinsuke
S
Bando
Yoshio
Y
Katayama
Taiichi
T
Tohyama
Masaya
M
D015687:Cell Hypoxia; D045744:Cell Line, Tumor; D015972:Gene Expression Regulation, Neoplastic; D025741:HMGA1a Protein / Q000378:metabolism*; D006801:Humans; D009447:Neuroblastoma / Q000378:metabolism*; D010100:Oxygen / Q000378:metabolism*; D010766:Phosphorylation; D016271:Proto-Oncogene Proteins c-myc / Q000378:metabolism*
D016271:Proto-Oncogene Proteins c-myc; D025741:HMGA1a Protein; D010100:Oxygen