Physical change in cytoplasmic messenger ribonucleoproteins in cells treated with inhibitors of mRNA transcription
Exposure of intact cells to UV light brings about cross-linking of polyadenylated mRNA to a set of cytoplasmic proteins which are in direct contact with the mRNA in vivo. Substantial amounts of an additional protein of molecular weight 38,000 become cross-linked to the mRNA when cells are treated with inhibitors of mRNA synthesis (actinomycin D, camptothecin, and 5,6-dichloro-1-beta-D-ribofuranosyl benzimidazole) or after infection with vesicular stomatitis virus. Cordycepin, which inhibits polyadenylation but not mRNA synthesis, has no such effect. Inhibitors of protein synthesis and of rRNA synthesis are also without effect on 38K cross-linking to mRNA. The onset of the effect of inhibitors of mRNA synthesis on the UV cross-linkable interaction between mRNA and 38K is rapid and reaches a maximal level in less than 60 min, and it is completely and rapidly reversible. In cells treated with actinomycin D, the amount of 38K which becomes cross-linked to mRNA is proportional to the extent of inhibition of mRNA synthesis. The association of 38K with mRNA during transcriptional arrest does not require protein synthesis because simultaneous treatment with the protein synthesis inhibitor emetine does not interfere with it. The effectors which promote the interaction of 38K with mRNA do not affect the proteins which are in contact with polyadenylated heterogeneous nuclear RNA and do not markedly affect protein synthesis in the cell. The 38K protein can be isolated with the polyribosomal polyadenylated fraction from which it was purified, and monoclonal antibodies against it were prepared.
- Research Organization:
- Department of Biochemistry, Molecular Biology and Cell Biology, Northwestern University, Evanston, Illinois
- OSTI ID:
- 6747591
- Journal Information:
- Mol. Cell. Biol.; (United States), Vol. 4:3
- Country of Publication:
- United States
- Language:
- English
Similar Records
Dependence of protein synthesis on transcription in pea cotyledons in early stages of germination
Serum-induced G0/G1 transition in chemically transformed 3T3 cells
Related Subjects
NUCLEOPROTEINS
BIOLOGICAL FUNCTIONS
TRANSCRIPTION
ENZYME INHIBITORS
HELA CELLS
MESSENGER-RNA
MONOCLONAL ANTIBODIES
RNA
ULTRAVIOLET RADIATION
VIRUSES
ANTIBODIES
ELECTROMAGNETIC RADIATION
FUNCTIONS
MICROORGANISMS
NUCLEIC ACIDS
ORGANIC COMPOUNDS
PARASITES
PROTEINS
RADIATIONS
550201* - Biochemistry- Tracer Techniques