Thymidylate synthase binds to c-myc RNA in human colon cancer cells and in vitro.
Using an immunoprecipitation-reverse transcription-PCR technique, we characterized a thymidylate synthase (TS) ribonucleoprotein complex in cultured human colon cancer cells that consists of TS protein and the mRNA of the nuclear oncogene c-myc. TS protein is complexed in intact cells with the C-terminal coding region of c-myc mRNA that includes nucleotide positions 1625 to 1790. RNA electrophoretic gel mobility shift assays confirm a specific interaction between TS protein and c-myc mRNA and provide additional evidence that the C-terminal coding region represents an important cis-acting regulatory element. Further evidence demonstrates that the in vitro translational efficiency of c-myc mRNA is inhibited as a result of its direct interaction with TS protein. In addition, the presence of exogenous c-myc mRNA specifically relieves the inhibitory effects of TS protein on TS mRNA translation.
Chu
E
E
NCI-Navy Medical Oncology Branch, Bethesda, Maryland 20892.
Takechi
T
T
Jones
K L
KL
Voeller
D M
DM
Copur
S M
SM
Maley
G F
GF
Maley
F
F
Segal
S
S
Allegra
C J
CJ
D001483:Base Sequence; D001665:Binding Sites; D003110:Colonic Neoplasms / Q000378:metabolism; D017931:DNA Primers / Q000737:chemistry; D005786:Gene Expression Regulation; D006801:Humans; D066298:In Vitro Techniques; D008969:Molecular Sequence Data; D011485:Protein Binding; D014176:Protein Biosynthesis; D016271:Proto-Oncogene Proteins c-myc / Q000235:genetics*; D012333:RNA, Messenger / Q000378:metabolism*; D016601:RNA-Binding Proteins / Q000378:metabolism*; D012261:Ribonucleoproteins / Q000737:chemistry; D013940:Thymidylate Synthase / Q000378:metabolism*; D014407:Tumor Cells, Cultured
D017931:DNA Primers; D016271:Proto-Oncogene Proteins c-myc; D012333:RNA, Messenger; D016601:RNA-Binding Proteins; D012261:Ribonucleoproteins; D013940:Thymidylate Synthase