TY - JOUR
T1 - TcUBP-1, an mRNA destabilizing factor from trypanosomes, homodimerizes and interacts with novel AU-rich element- and poly(A)-binding proteins forming a ribonucleoprotein complex
AU - D'Orso, Iván
AU - Frasch, Alberto C C
N1 - Copyright:
Copyright 2008 Elsevier B.V., All rights reserved.
PY - 2002/12/27
Y1 - 2002/12/27
N2 - Trypanosomes, protozoan parasites causing worldwide infections in human and animals, mostly regulate protein expression through post-transcriptional mechanisms and not at the transcription initiation level. We have previously identified a Trypanosoma cruzi RNA-binding protein named TcUBP-1. This protein is involved in mRNA destabilization in vivo through binding to AU-rich elements in the 3′-untranslated region of SMUG mucin mRNAs (D'Orso, I., and Frasch, A. C. (2001) J. Biol. Chem. 276, 34801-34809). In this work we show that TcUBP-1 is part of an -450-kDa ribonucleoprotein complex with a poly(A)-binding protein and a novel 18-kDa RNA-binding protein, named TcUBP-2. Recombinant TcUBP-1 and TcUBP-2 proteins recognize U-rich RNAs with similar specificity and affinity through the -92-amino acid RNA recognition motif. TcUBPs can homo- and heterodimerize in vitro through the glycine-rich C-terminal region. This interaction was also detected in vivo by co-immunoprecipitation of the ribonucleoprotein complex and using yeast two-hybrid assay. The poly(A)-binding protein identified was shown to disrupt the formation of TcUBP-1, but not TcUBP-2, homodimers in vitro. The possible role of TcUBP-1 ligands in the pathways that govern mRNA-stability and stage-specific expression in trypanosomes is discussed.
AB - Trypanosomes, protozoan parasites causing worldwide infections in human and animals, mostly regulate protein expression through post-transcriptional mechanisms and not at the transcription initiation level. We have previously identified a Trypanosoma cruzi RNA-binding protein named TcUBP-1. This protein is involved in mRNA destabilization in vivo through binding to AU-rich elements in the 3′-untranslated region of SMUG mucin mRNAs (D'Orso, I., and Frasch, A. C. (2001) J. Biol. Chem. 276, 34801-34809). In this work we show that TcUBP-1 is part of an -450-kDa ribonucleoprotein complex with a poly(A)-binding protein and a novel 18-kDa RNA-binding protein, named TcUBP-2. Recombinant TcUBP-1 and TcUBP-2 proteins recognize U-rich RNAs with similar specificity and affinity through the -92-amino acid RNA recognition motif. TcUBPs can homo- and heterodimerize in vitro through the glycine-rich C-terminal region. This interaction was also detected in vivo by co-immunoprecipitation of the ribonucleoprotein complex and using yeast two-hybrid assay. The poly(A)-binding protein identified was shown to disrupt the formation of TcUBP-1, but not TcUBP-2, homodimers in vitro. The possible role of TcUBP-1 ligands in the pathways that govern mRNA-stability and stage-specific expression in trypanosomes is discussed.
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U2 - 10.1074/jbc.M209092200
DO - 10.1074/jbc.M209092200
M3 - Article
C2 - 12403777
AN - SCOPUS:0037184949
SN - 0021-9258
VL - 277
SP - 50520
EP - 50528
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
IS - 52
ER -