Affinity purification of ARE-binding proteins identifies polyA-binding protein 1 as a potential substrate in MK2-induced mRNA stabilization.
An important determinant for the expression level of cytokines and proto-oncogenes is the rate of degradation of their mRNAs. AU-rich sequence elements (AREs) in the 3(') untranslated regions have been found to impose rapid decay of these mRNAs. ARE-containing mRNAs can be stabilized in response to external signals which activate the p38 MAP kinase cascade including the p38 MAP kinase substrate MAPKAP kinase 2 (MK2). In an attempt to identify components downstream of MK2 in this pathway we analyzed several proteins which selectively interact with the ARE of GM-CSF mRNA. One of them, the cytoplasmic poly(A)-binding protein PABP1, co-migrated with a protein that showed prominent phosphorylation by recombinant MK2. Phosphorylation by MK2 was confirmed using PABP1 purified by affinity chromatography on poly(A) RNA. The selective interaction with an ARE-containing RNA and the phosphorylation by MK2 suggest that PABP1 plays a regulatory role in ARE-dependent mRNA decay and its modulation by the p38 MAP kinase cascade.
Bollig
Frank
F
Institute of Pharmacology, Medical School Hannover, Germany.
Winzen
Reinhard
R
Gaestel
Matthias
M
Kostka
Susanne
S
Resch
Klaus
K
Holtmann
Helmut
H
D020413:3' Untranslated Regions; D001483:Base Sequence; D002846:Chromatography, Affinity; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000235:genetics* / Q000378:metabolism; D006367:HeLa Cells; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins; D010766:Phosphorylation; D039122:Poly(A)-Binding Protein I / Q000302:isolation & purification / Q000378:metabolism*; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D012313:RNA / Q000737:chemistry; D020871:RNA Stability; D012333:RNA, Messenger / Q000378:metabolism*; D016601:RNA-Binding Proteins / Q000302:isolation & purification / Q000378:metabolism; D012045:Regulatory Sequences, Nucleic Acid; D000099190:MAP-Kinase-Activated Kinase 2
D020413:3' Untranslated Regions; D016178:Granulocyte-Macrophage Colony-Stimulating Factor; D047908:Intracellular Signaling Peptides and Proteins; D039122:Poly(A)-Binding Protein I; D017346:Protein Serine-Threonine Kinases; D012313:RNA; D012333:RNA, Messenger; D016601:RNA-Binding Proteins; D000099190:MAP-Kinase-Activated Kinase 2