Abstract
Eukaryotic initiation factor 3 (eIF3), encapsulated in liposomes, is taken up by chick muscle cells in culture. The exogenously supplied factor (isolated from 14-d embryonic muscle) rapidly associated with 40S ribosomal subunits and particles sedimenting at 80-120S (the known sedimentation value of myosin heavy chain [MHC] mRNPs). In addition, exogenously supplied eIF3 has a specific stimulatory effect on myofibrillar protein synthesis. This stimulation is most apparent at the onset of cell fusion and after the accumulation of MHC-mRNPs. As previously reported (8), total eIF3 can be fractionated on an MHC-mRNA affinity column into a "core" eIF3 and a high affinity component (HAF) which dictates the discriminatory activity of core eIF3. Liposome- encapsulated core eIF3 delivered to cells is found predominantly in 40S ribosomal subunits and gives only a slight stimulation of total protein synthesis. When 3H-MHC-mRNA, preincubated with HAF, is introduced into myoblasts via liposomes, the mRNA is found in heavy polysomes. On the other hand, when the messenger alone or with core eIF3 is taken up by the cells, it is found only on small polysomes. Similar experiments, using viral RNA with the HAF, show no increase in the size class of polysomes. These results mimic the differences observed between myoblast and myotube utilization of MHC-mRNA previously observed (17). These results demonstrate the mRNA discriminatory activity of specific proteins associated with muscle eIF3 and suggest that these proteins play a role in mRNA activation and translation during muscle differentiation.
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Selected References
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- Benne R., Hershey J. W. The mechanism of action of protein synthesis initiation factors from rabbit reticulocytes. J Biol Chem. 1978 May 10;253(9):3078–3087. [PubMed] [Google Scholar]
- Bensadoun A., Weinstein D. Assay of proteins in the presence of interfering materials. Anal Biochem. 1976 Jan;70(1):241–250. doi: 10.1016/s0003-2697(76)80064-4. [DOI] [PubMed] [Google Scholar]
- Devlin R. B., Emerson C. P., Jr Coordinate regulation of contractile protein synthesis during myoblast differentiation. Cell. 1978 Apr;13(4):599–611. doi: 10.1016/0092-8674(78)90211-8. [DOI] [PubMed] [Google Scholar]
- Dimitriadis G. J. Translation of rabbit globin mRNA introduced by liposomes into mouse lymphocytes. Nature. 1978 Aug 31;274(5674):923–924. doi: 10.1038/274923a0. [DOI] [PubMed] [Google Scholar]
- Doetschman T. C., Dym H. P., Siegel E. J., Heywood S. M. Myoblast stored myosin heavy chain transcripts are precursors to the myotube polysomal myosin heavy chain mRNAs. Differentiation. 1980 Jun;16(3):149–162. doi: 10.1111/j.1432-0436.1980.tb01071.x. [DOI] [PubMed] [Google Scholar]
- Dym H. P., Kennedy D. S., Heywood S. M. Sub-cellular distribution of the cytoplasmic myosin heavy chain mRNA during myogenesis. Differentiation. 1979;12(3):145–155. doi: 10.1111/j.1432-0436.1979.tb01000.x. [DOI] [PubMed] [Google Scholar]
- Elson H. F., Yguerabide J. Membrane dynamics of differentiating cultured embryonic chick skeletal muscle cells by fluorescence microscopy techniques. J Supramol Struct. 1979;12(1):47–61. doi: 10.1002/jss.400120106. [DOI] [PubMed] [Google Scholar]
- Gette W. R., Heywood S. M. Translation of myosin heavy chain messenger ribonucleic acid in an eukaryotic initiation factor 3- and messenger-dependent muscle cell-free system. J Biol Chem. 1979 Oct 10;254(19):9879–9885. [PubMed] [Google Scholar]
- Heywood S. M., Kennedy D. S., Bester A. J. Stored myosin messenger in embryonic chick muscle. FEBS Lett. 1975 Apr 15;53(1):69–72. doi: 10.1016/0014-5793(75)80684-3. [DOI] [PubMed] [Google Scholar]
- Heywood S. M., Kennedy D. S. Messenger RNA affinity column fractionation of eukaryotic initiation factor and the translation of myosin messenger RNA. Arch Biochem Biophys. 1979 Jan;192(1):270–281. doi: 10.1016/0003-9861(79)90092-4. [DOI] [PubMed] [Google Scholar]
- Jentoft N., Dearborn D. G. Labeling of proteins by reductive methylation using sodium cyanoborohydride. J Biol Chem. 1979 Jun 10;254(11):4359–4365. [PubMed] [Google Scholar]
- Laskey R. A., Mills A. D. Quantitative film detection of 3H and 14C in polyacrylamide gels by fluorography. Eur J Biochem. 1975 Aug 15;56(2):335–341. doi: 10.1111/j.1432-1033.1975.tb02238.x. [DOI] [PubMed] [Google Scholar]
- Lodish H. F. Model for the regulation of mRNA translation applied to haemoglobin synthesis. Nature. 1974 Oct 4;251(5474):385–388. doi: 10.1038/251385a0. [DOI] [PubMed] [Google Scholar]
- MacKeen L. A., DiPeri C., Schwartz I. Reductive methylation of IF-3 and EFTu with [14C]formaldehyde and sodium cyanoborohydride. FEBS Lett. 1979 May 15;101(2):387–390. doi: 10.1016/0014-5793(79)81050-9. [DOI] [PubMed] [Google Scholar]
- Morse R. K., Herrmann H., Heywood S. M. Extraction with Triton X-100 of active polysomes from monolayer cultures of embryonic muscle cells. Biochim Biophys Acta. 1971 Mar 11;232(2):403–409. doi: 10.1016/0005-2787(71)90593-4. [DOI] [PubMed] [Google Scholar]
- Mroczkowski B., Dym H. P., Siegel E. J., Heywood S. M. Uptake and utilization of mRNA by myogenic cells in culture. J Cell Biol. 1980 Oct;87(1):65–71. doi: 10.1083/jcb.87.1.65. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Ostro M. J., Lavelle D., Paxton W., Matthews B., Giacomoni D. Parameters affecting the liposome-mediated insertion of RNA into eucaryotic cells in vitro. Arch Biochem Biophys. 1980 May;201(2):392–402. doi: 10.1016/0003-9861(80)90527-5. [DOI] [PubMed] [Google Scholar]
- Paphadjopoulos D., Wilson T., Taber R. Liposomes as vehicles for cellular incorporation of biologically active macromolecules. In Vitro. 1980 Jan;16(1):49–54. doi: 10.1007/BF02618199. [DOI] [PubMed] [Google Scholar]
- Rourke A. W., Heywood S. M. Myosin synthesis and specificity of eukaryotic initiation factors. Biochemistry. 1972 May 23;11(11):2061–2066. doi: 10.1021/bi00761a010. [DOI] [PubMed] [Google Scholar]
- Szoka F., Jr, Papahadjopoulos D. Comparative properties and methods of preparation of lipid vesicles (liposomes). Annu Rev Biophys Bioeng. 1980;9:467–508. doi: 10.1146/annurev.bb.09.060180.002343. [DOI] [PubMed] [Google Scholar]
- Tepperman K., Morris G., Essien F., Heywood S. M. A mechanical dissociation method for preparation of muscle cell cultures. J Cell Physiol. 1975 Dec;86(3 Pt 1):561–565. doi: 10.1002/jcp.1040860313. [DOI] [PubMed] [Google Scholar]
- Trachsel H., Erni B., Schreier M. H., Staehelin T. Initiation of mammalian protein synthesis. II. The assembly of the initiation complex with purified initiation factors. J Mol Biol. 1977 Nov;116(4):755–767. doi: 10.1016/0022-2836(77)90269-8. [DOI] [PubMed] [Google Scholar]
- Wilson T., Papahadjopoulos D., Taber R. Biological properties of poliovirus encapsulated in lipid vesicles: antibody resistance and infectivity in virus-resistant cells. Proc Natl Acad Sci U S A. 1977 Aug;74(8):3471–3475. doi: 10.1073/pnas.74.8.3471. [DOI] [PMC free article] [PubMed] [Google Scholar]
