A Novel eIF5A Complex Functions As a Regulator of p53 and p53-dependent Apoptosis

Autor: Xue-Min Zhang, Mei Ru Hu, Jiang Hong Man, Xiaodan Yu, Ai-Ling Li, Tao Zhou, Xin Pan, Song Cheng Yang, Jie Wang, Ming Yu, Bei Fen Shen, Kun He, Qi Nong Ye, Bao Feng Jin, Hui Yan Li
Rok vydání: 2004
Předmět:
Small interfering RNA
Time Factors
Syntenins
Regulator
Apoptosis
Biochemistry
Peptide Initiation Factors
RNA interference
Fluorescence Resonance Energy Transfer
Phosphorylation
RNA
Small Interfering
Glutathione Transferase
bcl-2-Associated X Protein
Regulation of gene expression
Inhibitor of apoptosis domain
biology
Reverse Transcriptase Polymerase Chain Reaction
Intracellular Signaling Peptides and Proteins
RNA-Binding Proteins
Flow Cytometry
Up-Regulation
Proto-Oncogene Proteins c-bcl-2
COS Cells
RNA Interference
EIF5A
Plasmids
Protein Binding
DNA
Complementary
Blotting
Western
Green Fluorescent Proteins
Transfection
Cell Line
Proto-Oncogene Proteins p21(ras)
Bcl-2-associated X protein
Cell Line
Tumor
Two-Hybrid System Techniques
Animals
Humans
Immunoprecipitation
Point Mutation
Initiation factor
Gene Silencing
Molecular Biology
Membrane Proteins
Cell Biology
Protein Structure
Tertiary
Gene Expression Regulation
Mutation
biology.protein
Cancer research
Tumor Suppressor Protein p53
Zdroj: Journal of Biological Chemistry. 279:49251-49258
ISSN: 0021-9258
DOI: 10.1074/jbc.m407165200
Popis: Although eukaryotic translation initiation factor 5A (eIF5A) was originally designated as an "initiation factor," recent data have shown it to be also involved in apoptosis. However, the actual function of eIF5A in apoptosis is still unknown. In this study, we performed yeast two-hybrid screens to identify eIF5A-interacting proteins to help us understand the mechanisms of eIF5A. Our results demonstrated that eIF5A and syntenin could engage in a specific interaction both in vitro and in vivo and functioned collaboratively to regulate p53 activity. Our findings, for the first time, revealed a new biological activity for eIF5A as the regulator of p53. Overexpression of eIF5A or its EFP domain resulted in up-regulation of p53, and silencing eIF5A by small interfering RNA reduced the p53 protein level. Further analysis by reverse transcription PCR showed eIF5A-activated p53 transcription. The effect of eIF5A on p53 transcriptional activity was further demonstrated by the increasing expressions of p21 and Bax, well known target genes of p53. In contrast, a point mutant of eIF5A, hypusination being abolished, was revealed to be functionally defective in p53 up-regulation. Overexpression of eIF5A led to a p53-dependent apoptosis or sensitized cells to induction of apoptosis by chemotherapeutic agents. However, when eIF5A interacted with its novel partner, syntenin, the eIF5A-induced increase in p53 protein level was significantly inhibited. Therefore, eIF5A seems to be a previously unrecognized regulator of p53 that may define a new pathway for p53-dependent apoptosis, and syntenin might regulate p53 by balancing the regulation of eIF5A signaling to p53 for apoptosis.
Databáze: OpenAIRE
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