Poly(A) shortening and degradation of the 3' A+U-rich sequences of human c-myc mRNA in a cell-free system

Journal Article · Fri Apr 01 04:00:00 EST 1988 · Mol. Cell. Biol.; (United States)

DOI:https://doi.org/10.1128/MCB.8.4.1697· OSTI ID:7027449

Brewer, G; Ross, J

The early steps in the degradation of human c-myc mRNA were investigated, using a previously described cell-free mRNA decay system. The first detectable step was poly(A) shortening, which generated a pool of oligoadenylated mRNA molecules. In contrast, the poly(A) of a stable mRNA, ..gamma.. globin, was not excised, even after prolonged incubation. The second step, degradation of oligoadenylated c-myc mRNA, generated decay products whose 3' termini were located within the A+U-rich portion of the 3' untranslated region. These products disappeared soon after they were formed, consistent with rapid degradation of the 3' region. In contrast, the 5' region, corresponding approximately to c-myc exon 1, was stable in vitro. The data indicate a sequential degradation pathway in which 3' region cleavages occur only after most or all of the poly(A) is removed. To account for rapid deadenylation, the authors suggest that the c-myc poly(A)-poly(A)-binding protein complex is readily dissociated, generating a protein-depleted poly(A) tract that is no longer resistant to nucleases.

• Research Organization: McArdle Lab. for Cancer Research and Dept. of Pathology, Univ. of Wisconsin, 450 North Randall Avenue, Madison, WI (US)
• OSTI ID: 7027449
• Journal Information: Mol. Cell. Biol.; (United States), Journal Name: Mol. Cell. Biol.; (United States) Vol. 8:4; ISSN MCEBD
• Country of Publication: United States
• Language: English

Related Subjects

550200* -- Biochemistry
59 BASIC BIOLOGICAL SCIENCES
BIODEGRADATION
BIOLOGICAL PATHWAYS
CHEMICAL REACTIONS
CLEAVAGE
CRYSTAL STRUCTURE
DECOMPOSITION
DNA SEQUENCING
DNA-ASE
ENDONUCLEASES
ENZYME ACTIVITY
ENZYMES
ESTERASES
GENE RECOMBINATION PROTEINS
GLOBIN
HYDROLASES
MESSENGER-RNA
MICROSTRUCTURE
MOLECULAR STRUCTURE
NUCLEIC ACIDS
NUCLEOPROTEINS
ORGANIC COMPOUNDS
PHOSPHODIESTERASES
PROTEINS
RNA
STRUCTURAL CHEMICAL ANALYSIS