Evidence for a 3′-5′ Decay Pathway for c-mycmRNA in Mammalian Cells

Brewer, Gary

doi:10.1074/jbc.274.23.16174

Cited by 43 publications

(56 citation statements)

References 30 publications

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“…The blot was hybridized with a 32 P-labeled probe specific to the 3Ј-end of c-myc mRNA to visualize poly(A) tract lengths. Consistent with earlier results (18,19), the time-zero RNA showed a broad band indicative of heterogeneous lengths of poly(A) tracts within the population of c-myc mRNA molecules at the time of cell lysis (Fig. 5A, lane 1).…”

Section: Tpa-induced Differentiation and Down-regulation Of C-mycsupporting

confidence: 78%

“…Its decay then continues in a 3Ј35Ј direction (18). c-myc mRNA decays via this pathway in vitro as well (19,20).…”

mentioning

confidence: 99%

“…In some experiments 10-g aliquots of RNA from each time point were separated into poly(A ϩ ) and poly(A Ϫ ) fractions by batch adsorption and elution with oligo(dT)-cellulose as described (18). ␥-Globin mRNA was detected by S1 nuclease mapping as described (18). c-myc, PDGF-B, TGF-␤1, and ␤-actin mRNAs were detected by RNase P1ϩT1 protection assays as described (19).…”

mentioning

confidence: 99%

“…RNA concentrations were determined spectrophotometrically by absorption at 260 nm. In some experiments 10-g aliquots of RNA from each time point were separated into poly(A ϩ ) and poly(A Ϫ ) fractions by batch adsorption and elution with oligo(dT)-cellulose as described (18). ␥-Globin mRNA was detected by S1 nuclease mapping as described (18).…”

mentioning

confidence: 99%

“…RNase H Mapping Analysis of Poly(A) Tract Lengths-10 g of each RNA sample was subjected to oligonucleotide-directed RNase H cleavage exactly as described (18) using an antisense c-myc oligodeoxynucleotide (5Ј-CAAGTTCATAGGTGATTGCTG-3Ј), which anneals approximately 400 nt upstream of poly(A) site 2 (19). RNA samples were then fractionated in a denaturing agarose gel and blotted to a membrane.…”

mentioning

confidence: 99%

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Regulation of c-myc mRNA Decay in Vitro by a Phorbol Ester-inducible, Ribosome-associated Component in Differentiating Megakaryoblasts

Brewer¹

2000

Journal of Biological Chemistry

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The K562 leukemia cell line is bipotential for erythroid and megakaryoblastic differentiation. The phorbol ester 12-O-tetradecanoylphorbol-13-acetate (TPA) activates a genetic program of gene expression in these cells leading to their differentiation into megakaryoblasts, a platelet precursor. Thus, K562 cells offer a means to examine early changes in gene expression necessary for megakaryoblastic commitment and differentiation. An essential requirement for differentiation of many hematopoietic cell types is the down-regulation of c-myc expression, because its constitutive expression blocks differentiation. TPA-induced differentiation of K562 cells causes rapid down-regulation of c-myc expression, due in part to an mRNA decay rate that is 4-fold faster compared with dividing cells. A cell-free mRNA decay system reconstitutes TPA-induced destabilization of c-myc mRNA, but it requires at least two components for reconstitution. One component fractionates to the postribosomal supernatant from either untreated or treated cells. This component is sensitive to cycloheximide and micrococcal nuclease. The other component is polysome-associated and is induced or activated by TPA. Although in dividing cells c-myc mRNA decays via a sequential pathway involving removal of the poly(A) tract followed by degradation of the mRNA body, TPA activates a deadenylation-independent pathway. The cell-free mRNA decay system reconstitutes this alternate decay pathway as well.

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Section: Tpa-induced Differentiation and Down-regulation Of C-mycsupporting

confidence: 78%

“…Its decay then continues in a 3Ј35Ј direction (18). c-myc mRNA decays via this pathway in vitro as well (19,20).…”

mentioning

confidence: 99%

mentioning

confidence: 99%

mentioning

confidence: 99%

mentioning

confidence: 99%

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Regulation of c-myc mRNA Decay in Vitro by a Phorbol Ester-inducible, Ribosome-associated Component in Differentiating Megakaryoblasts

Brewer¹

2000

Journal of Biological Chemistry

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Purification and characterization of a novel mammalian endoribonuclease

Bergstrom¹,

Urquhart²,

Tafech³

et al. 2005

J of Cellular Biochemistry

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Endonuclease-mediated mRNA decay appears to be a common mode of mRNA degradation in mammalian cells, but yet only a few mRNA endonucleases have been described. Here, we report the existence of a second mammalian endonuclease that is capable of cleaving c-myc mRNA within the coding region in vitro. This study describes the partial purification and biochemical characterization of this enzyme. Five major proteins of approximately 10-35 kDa size co-purified with the endonuclease activity, a finding supported by gel filtration and glycerol gradient centrifugation analysis. The enzyme is an RNA-specific endonuclease that degrades single-stranded RNA, but not double-stranded RNA, DNA or DNA-RNA duplexes. It preferentially cleaves RNA in between the pyrimidine and purine dinucleotides UA, UG, and CA, at the coding region determinant (CRD) of c-myc RNA. The enzyme generates products with a 3'hydroxyl group, and it appears to be a protein-only endonuclease. It does not possess RNase A-like activity. The enzyme is capable of cleaving RNAs other than c-myc CRD RNA in vitro. It is Mg(2+)-independent and is resistant to EDTA. The endonuclease is inactivated at and above 70 degrees C. These properties distinguished the enzyme from other previously described vertebrate endonucleases.

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The role of AUF1 in regulated mRNA decay

2010

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Messenger ribonucleic acid (mRNA) turnover is a major control point in gene expression. In mammals, many mRNAs encoding inflammatory cytokines, oncoproteins, and G-protein-coupled receptors are destabilized by the presence of AU-rich elements (AREs) in their 3′-untranslated regions. Association of ARE-binding proteins (AUBPs) with these mRNAs promotes rapid mRNA degradation. ARE/poly(U)-binding/degradation factor 1 (AUF1), one of the best-characterized AUBPs, binds to many ARE-mRNAs and assembles other factors necessary to recruit the mRNA degradation machinery. These factors include translation initiation factor eIF4G, chaperones hsp27 and hsp70, heat-shock cognate protein hsc70, lactate dehydrogenase, poly(A)-binding protein, and other unidentified proteins. Numerous signaling pathways alter the composition of this AUF1 complex of proteins to effect changes in ARE-mRNA degradation rates. This review briefly describes the roles of mRNA decay in gene expression in general and ARE-mediated decay (AMD) in particular, with a focus on AUF1 and the different modes of regulation that govern AUF1 involvement in AMD.

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Evidence for a 3′-5′ Decay Pathway for c-mycmRNA in Mammalian Cells

Cited by 43 publications

References 30 publications

Regulation of c-myc mRNA Decay in Vitro by a Phorbol Ester-inducible, Ribosome-associated Component in Differentiating Megakaryoblasts

Regulation of c-myc mRNA Decay in Vitro by a Phorbol Ester-inducible, Ribosome-associated Component in Differentiating Megakaryoblasts

Purification and characterization of a novel mammalian endoribonuclease

The role of AUF1 in regulated mRNA decay

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