CRD-BP protects the coding region of betaTrCP1 mRNA from miR-183-mediated degradation.

miRNAs are largely known to base pair with the 3'UTR of target mRNAs, downregulating their stability and translation. mRNA of betaTrCP1 ubiquitin ligase is very unstable, but unlike the majority of mRNAs where 3'UTR determines the rate of mRNA turnover, betaTrCP1 mRNA contains cis-acting destabilizing elements within its coding region. Here we show that degradation of mRNA of betaTrCP1 is miRNA dependent and identify miR-183 as a microRNA that interacts with the coding region of betaTrCP1 mRNA. Argonaute2 interacts with the same region of betaTrCP1 mRNA in an miR-183-dependent manner. Inhibition of miR-183 function or disruption of the miR-183-binding site stabilizes betaTrCP1 mRNA and elevates betaTrCP1 levels, resulting in activation of the SCF(betaTrCP) E3 ubiquitin ligase. We previously showed that the RNA-binding protein CRD-BP binds to the coding region of betaTrCP1 mRNA and stabilizes it. Here we demonstrate that CRD-BP prevents degradation of betaTrCP1 mRNA by attenuating its miR-183-dependent interaction with Ago2.

[1]  Charles R. Tessier,et al.  Mammary Tumor Induction in Transgenic Mice Expressing an RNA-Binding Protein , 2004, Cancer Research.

[2]  T. Tuschl,et al.  Human Argonaute2 mediates RNA cleavage targeted by miRNAs and siRNAs. , 2004, Molecular cell.

[3]  S. Fuchs,et al.  CRD-BP mediates stabilization of βTrCP1 and c-myc mRNA in response to β-catenin signalling , 2006, Nature.

[4]  J. Castle,et al.  Microarray analysis shows that some microRNAs downregulate large numbers of target mRNAs , 2005, Nature.

[5]  I. Lemm,et al.  Overexpression of an mRNA-binding protein in human colorectal cancer , 2001, Oncogene.

[6]  D. Doolittle,et al.  Quantification of changes in c-myc mRNA levels in normal human bronchial epithelial (NHBE) and lung adenocarcinoma (A549) cells following chemical treatment. , 2001, Toxicological sciences : an official journal of the Society of Toxicology.

[7]  Subramanya,et al.  p16 Translation Suppressed by miR-24 , 2008 .

[8]  D. St Johnston,et al.  A repeated IMP-binding motif controls oskar mRNA translation and anchoring independently of Drosophila melanogaster IMP , 2006, The Journal of cell biology.

[9]  X. Agirre,et al.  Identification by Real-time PCR of 13 mature microRNAs differentially expressed in colorectal cancer and non-tumoral tissues , 2006, Molecular Cancer.

[10]  Ligang Wu,et al.  MicroRNAs direct rapid deadenylation of mRNA. , 2006, Proceedings of the National Academy of Sciences of the United States of America.

[11]  J. Steitz,et al.  Target mRNAs are repressed as efficiently by microRNA-binding sites in the 5′ UTR as in the 3′ UTR , 2007, Proceedings of the National Academy of Sciences.

[12]  W. Filipowicz,et al.  Mechanisms of post-transcriptional regulation by microRNAs: are the answers in sight? , 2008, Nature Reviews Genetics.

[13]  E. Furth,et al.  Augmentation of tumor angiogenesis by a Myc-activated microRNA cluster , 2006, Nature Genetics.

[14]  C. Burge,et al.  Conserved Seed Pairing, Often Flanked by Adenosines, Indicates that Thousands of Human Genes are MicroRNA Targets , 2005, Cell.

[15]  T. Slaga,et al.  Inhibition of HOS expression and activities by Wnt pathway , 2002, Oncogene.

[16]  J. Ross,et al.  Purification and properties of a protein that binds to the C-terminal coding region of human c-myc mRNA. , 1994, The Journal of biological chemistry.

[17]  Reuven Agami,et al.  miR-148 targets human DNMT3b protein coding region. , 2008, RNA.

[18]  Anton J. Enright,et al.  Zebrafish MiR-430 Promotes Deadenylation and Clearance of Maternal mRNAs , 2006, Science.

[19]  Chow H Lee,et al.  CRD-BP shields c-myc and MDR-1 RNA from endonucleolytic attack by a mammalian endoribonuclease , 2007, Nucleic acids research.

[20]  S. Fuchs,et al.  The many faces of β-TrCP E3 ubiquitin ligases: reflections in the magic mirror of cancer , 2004, Oncogene.

[21]  L. Lim,et al.  An Abundant Class of Tiny RNAs with Probable Regulatory Roles in Caenorhabditis elegans , 2001, Science.

[22]  K. Livak,et al.  Real-time quantification of microRNAs by stem–loop RT–PCR , 2005, Nucleic acids research.

[23]  R. Giegerich,et al.  Fast and effective prediction of microRNA/target duplexes. , 2004, RNA.

[24]  Martin J. Simard,et al.  Argonaute proteins: key players in RNA silencing , 2008, Nature Reviews Molecular Cell Biology.

[25]  T. Slaga,et al.  Wnt/beta-catenin signaling induces the expression and activity of betaTrCP ubiquitin ligase receptor. , 2000, Molecular cell.

[26]  R. Plasterk,et al.  Substrate requirements for let-7 function in the developing zebrafish embryo. , 2004, Nucleic acids research.

[27]  F. Nielsen,et al.  A family of IGF-II mRNA binding proteins (IMP) involved in RNA trafficking. , 2001, Scandinavian journal of clinical and laboratory investigation. Supplementum.

[28]  Yvonne Tay,et al.  MicroRNAs to Nanog, Oct4 and Sox2 coding regions modulate embryonic stem cell differentiation , 2009, Nature.

[29]  T. Slaga,et al.  Induction of β-Transducin Repeat-containing Protein by JNK Signaling and Its Role in the Activation of NF-κB* , 2001, The Journal of Biological Chemistry.

[30]  W. Bennett,et al.  Identification of c-myc coding region determinant RNA sequences and structures cleaved by an RNase1-like endoribonuclease. , 2007, Biochimica et biophysica acta.

[31]  T. Hansen,et al.  Dwarfism and Impaired Gut Development in Insulin-Like Growth Factor II mRNA-Binding Protein 1-Deficient Mice , 2004, Molecular and Cellular Biology.

[32]  S. Cohen,et al.  microRNA functions. , 2007, Annual review of cell and developmental biology.

[33]  Brian S. Roberts,et al.  The colorectal microRNAome. , 2006, Proceedings of the National Academy of Sciences of the United States of America.

[34]  Michael Zuker,et al.  MicroRNA-responsive 'sensor' transgenes uncover Hox-like and other developmentally regulated patterns of vertebrate microRNA expression , 2004, Nature Genetics.

[35]  Joshua J. Forman,et al.  A search for conserved sequences in coding regions reveals that the let-7 microRNA targets Dicer within its coding sequence , 2008, Proceedings of the National Academy of Sciences.

[36]  S. Fuchs,et al.  CRD-BP mediates stabilization of betaTrCP1 and c-myc mRNA in response to beta-catenin signalling. , 2006, Nature.