p53 targets identified by protein expression profiling.
p53 triggers cell cycle arrest and apoptosis through transcriptional regulation of specific target genes. We have investigated the effect of p53 activation on the proteome using 2D gel electrophoresis analysis of mitomycin C-treated HCT116 colon carcinoma cells carrying wild-type p53. Approximately 5,800 protein spots were separated in overlapping narrow-pH-range gel strips, and 115 protein spots showed significant expression changes upon p53 activation. The identity of 55 protein spots was obtained by mass spectrometry. The majority of the identified proteins have no previous connection to p53. The proteins fall into different functional categories, such as mRNA processing, translation, redox regulation, and apoptosis, consistent with the idea that p53 regulates multiple cellular pathways. p53-dependent regulation of five of the up-regulated proteins, eIF5A, hnRNP C1/C2, hnRNP K, lamin A/C, and Nm23-H1, and two of the down-regulated proteins, Prx II and TrpRS, was examined in further detail. Analysis of mRNA expression levels demonstrated both transcription-dependent and transcription-independent regulation among the identified targets. Thus, this study reveals protein targets of p53 and highlights the role of transcription-independent effects for the p53-induced biological response.
Rahman-Roblick
Rubaiyat
R
Department of Oncology-Pathology, Cancer Center Karolinska, Karolinska Institutet, SE-171 76 Stockholm, Sweden.
Roblick
Uwe Johannes
UJ
Hellman
Ulf
U
Conrotto
Paolo
P
Liu
Tao
T
Becker
Susanne
S
Hirschberg
Daniel
D
Jörnvall
Hans
H
Auer
Gert
G
Wiman
Klas G
KG
D017209:Apoptosis; D045744:Cell Line, Tumor; D003110:Colonic Neoplasms / Q000378:metabolism; D015180:Electrophoresis, Gel, Two-Dimensional; D020869:Gene Expression Profiling; D006801:Humans; D006863:Hydrogen-Ion Concentration; D013058:Mass Spectrometry; D016685:Mitomycin / Q000494:pharmacology; D009362:Neoplasm Metastasis; D009369:Neoplasms / Q000378:metabolism; D010084:Oxidation-Reduction; D011401:Promoter Regions, Genetic; D040901:Proteomics / Q000379:methods; D016159:Tumor Suppressor Protein p53 / Q000096:biosynthesis* / Q000737:chemistry
C495901:TP53 protein, human; D016159:Tumor Suppressor Protein p53; D016685:Mitomycin