Identification of Nucleolin as an AU-rich Element Binding Protein Involved in bcl-2 mRNA Stabilization

bcl-2 mRNA contains an AU-rich element (ARE) that functions in regulating bcl-2 stability. Our earlier studies indicated that taxol- or okadaic acid-induced bcl-2 mRNA destabilization in HL-60 cells is associated with decreased binding of trans-acting factors to the ARE. To identify factors that pla...

Full description

Saved in:
Bibliographic Details
Published in:The Journal of biological chemistry 2004-03, Vol.279 (12), p.10855-10863
Main Authors: Sengupta, Tapas K., Bandyopadhyay, Sumita, Fernandes, Daniel J., Spicer, Eleanor K.
Format: Article
Language:English
Subjects:
Apoptosis - drug effects
Genes, bcl-2
HL-60 Cells
Humans
Nucleolin
Okadaic Acid - pharmacology
Paclitaxel - pharmacology
Phosphoproteins - chemistry
Phosphoproteins - drug effects
Phosphoproteins - physiology
Protein Binding
RNA, Messenger - chemistry
RNA, Messenger - genetics
RNA-Binding Proteins - chemistry
RNA-Binding Proteins - drug effects
RNA-Binding Proteins - physiology
Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:bcl-2 mRNA contains an AU-rich element (ARE) that functions in regulating bcl-2 stability. Our earlier studies indicated that taxol- or okadaic acid-induced bcl-2 mRNA destabilization in HL-60 cells is associated with decreased binding of trans-acting factors to the ARE. To identify factors that play a role in the regulation of bcl-2 mRNA stability, bcl-2 ARE-binding proteins were purified from HL-60 cells. Three polypeptides of 100, 70, and 32 kDa were isolated from a bcl-2 ARE affinity matrix. Matrix-assisted laser desorption ionization mass spectroscopy analysis identified these proteins as full-length nucleolin and proteolytic fragments of nucleolin. RNA gel shifts assays indicated that recombinant nucleolin (residues 284–707) binds specifically to bcl-2 ARE RNA. In addition, recombinant nucleolin decreases the rate of decay of mRNA in HL-60 cell extracts in an ARE-dependent manner. Taxol or okadaic acid treatment of HL-60 cells results in proteolysis of nucleolin in a similar time frame as drug-induced bcl-2 mRNA down-regulation. These findings suggest that nucleolin functions as a bcl-2-stabilizing factor and that taxol and okadaic acid treatment induces apoptosis in HL-60 cells through a process that involves down-regulation of nucleolin and destabilization of bcl-2 mRNA.
ISSN:0021-9258
1083-351X
DOI:10.1074/jbc.M309111200