Abstract
The role of cell configuration in regulating cell metabolism has been studied, using a system in which cell shape and surface contact can easily be manipulated. The suspension of anchorage-dependent mouse fibroblasts in Methocel results in a coordinate decrease of DNA, RNA, and protein synthesis. These processes are restored upon reattachment of cells to a solid surface. This recovery process has two or more components: a rapid recovery of protein synthesis requiring only surface contact, and a slower restoration of nuclear events which is dependent upon extensive cell spreading (A. Ben-Ze'ev, S.R. Farmer, and S. Penman, Cell 21:365-372, 1980). In the present study, we examined 3T3 cells while in suspension culture and after attachment to a tissue culture dish surface to study cell configuration-dependent expression of specific cytoskeleton protein genes. The 3T3 line of fibroblasts used here shows these responses much more dramatically compared with 3T6 cells previously studied. We demonstrate that whereas total protein synthesis was strongly inhibited upon suspension, actin synthesis was preferentially inhibited, decreasing from 12% of total protein synthesis in control cells to 6% in suspended cells. This occurred apparently at the level of translation of actin mRNA, since the amount of actin mRNA sequences in the cytoplasm was unchanged. Reattachment initiated the rapid recovery of overall protein synthesis which was accompanied by a dramatic, preferential increase in actin synthesis reaching peak values of 20 to 25% of total protein synthesis 4 to 6 h later, but then declining to control values by 24 h. Translation in vitro and hybridization of mRNA to a cloned actin cDNA probe revealed that the induction of actin synthesis was due to increased levels of translatable mRNA sequences in the cytoplasm. These results imply a close relationship among cell cytoarchitecture, expression of a specific cytoskeletal protein gene, and growth control. The expression of the actin gene appears to be regulated at both the level of translation (during suspension) and mRNA production (during recovery).
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- Ben-Ze'ev A., Farmer S. R., Penman S. Mechanisms of regulating tubulin synthesis in cultured mammalian cells. Cell. 1979 Jun;17(2):319–325. doi: 10.1016/0092-8674(79)90157-0. [DOI] [PubMed] [Google Scholar]
- Ben-Ze'ev A., Farmer S. R., Penman S. Protein synthesis requires cell-surface contact while nuclear events respond to cell shape in anchorage-dependent fibroblasts. Cell. 1980 Sep;21(2):365–372. doi: 10.1016/0092-8674(80)90473-0. [DOI] [PubMed] [Google Scholar]
- Benecke B. J., Ben-Ze'ev A., Penman S. The control of mRNA production, translation and turnover in suspended and reattached anchorage-dependent fibroblasts. Cell. 1978 Aug;14(4):931–939. doi: 10.1016/0092-8674(78)90347-1. [DOI] [PubMed] [Google Scholar]
- Benecke B. J., Ben-Ze'ev A., Penman S. The regulation of RNA metabolism in suspended and reattached anchorage-dependent 3T6 fibroblasts. J Cell Physiol. 1980 May;103(2):247–254. doi: 10.1002/jcp.1041030209. [DOI] [PubMed] [Google Scholar]
- Bishop J. O., Rosbash M. Polynucleotide sequences in eukaryotic DNA and RNA that form ribonuclease-resistant complexes with polyuridylic acid. J Mol Biol. 1974 May 5;85(1):75–86. doi: 10.1016/0022-2836(74)90130-2. [DOI] [PubMed] [Google Scholar]
- Bonner W. M., Laskey R. A. A film detection method for tritium-labelled proteins and nucleic acids in polyacrylamide gels. Eur J Biochem. 1974 Jul 1;46(1):83–88. doi: 10.1111/j.1432-1033.1974.tb03599.x. [DOI] [PubMed] [Google Scholar]
- Cleveland D. W., Lopata M. A., MacDonald R. J., Cowan N. J., Rutter W. J., Kirschner M. W. Number and evolutionary conservation of alpha- and beta-tubulin and cytoplasmic beta- and gamma-actin genes using specific cloned cDNA probes. Cell. 1980 May;20(1):95–105. doi: 10.1016/0092-8674(80)90238-x. [DOI] [PubMed] [Google Scholar]
- Cleveland D. W., Lopata M. A., Sherline P., Kirschner M. W. Unpolymerized tubulin modulates the level of tubulin mRNAs. Cell. 1981 Aug;25(2):537–546. doi: 10.1016/0092-8674(81)90072-6. [DOI] [PubMed] [Google Scholar]
- Farmer S. R., Ben-Ze'av A., Benecke B. J., Penman S. Altered translatability of messenger RNA from suspended anchorage-dependent fibroblasts: reversal upon cell attachment to a surface. Cell. 1978 Oct;15(2):627–637. doi: 10.1016/0092-8674(78)90031-4. [DOI] [PubMed] [Google Scholar]
- Folkman J., Greenspan H. P. Influence of geometry on control of cell growth. Biochim Biophys Acta. 1975 Dec 31;417(3-4):211–236. doi: 10.1016/0304-419x(75)90011-6. [DOI] [PubMed] [Google Scholar]
- Folkman J., Moscona A. Role of cell shape in growth control. Nature. 1978 Jun 1;273(5661):345–349. doi: 10.1038/273345a0. [DOI] [PubMed] [Google Scholar]
- Kaufmann Y., Milcarek C., Berissi H., Penman S. HeLa cell poly(A)- mRNA codes for a subset of poly(A)+ mRNA-directed proteins with an actin as a major product. Proc Natl Acad Sci U S A. 1977 Nov;74(11):4801–4805. doi: 10.1073/pnas.74.11.4801. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Laemmli U. K. Cleavage of structural proteins during the assembly of the head of bacteriophage T4. Nature. 1970 Aug 15;227(5259):680–685. doi: 10.1038/227680a0. [DOI] [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]
- Lemischka I. R., Farmer S., Racaniello V. R., Sharp P. A. Nucleotide sequence and evolution of a mammalian alpha-tubulin messenger RNA. J Mol Biol. 1981 Sep 5;151(1):101–120. doi: 10.1016/0022-2836(81)90223-0. [DOI] [PubMed] [Google Scholar]
- Merril C. R., Goldman D., Sedman S. A., Ebert M. H. Ultrasensitive stain for proteins in polyacrylamide gels shows regional variation in cerebrospinal fluid proteins. Science. 1981 Mar 27;211(4489):1437–1438. doi: 10.1126/science.6162199. [DOI] [PubMed] [Google Scholar]
- O'Farrell P. H. High resolution two-dimensional electrophoresis of proteins. J Biol Chem. 1975 May 25;250(10):4007–4021. [PMC free article] [PubMed] [Google Scholar]
- Otsuka H., Moskowitz M. Arrest of 3T3 cells in G1 phase in suspension culture. J Cell Physiol. 1975 Dec;87(2):213–219. doi: 10.1002/jcp.1040870209. [DOI] [PubMed] [Google Scholar]
- Pelham H. R., Jackson R. J. An efficient mRNA-dependent translation system from reticulocyte lysates. Eur J Biochem. 1976 Aug 1;67(1):247–256. doi: 10.1111/j.1432-1033.1976.tb10656.x. [DOI] [PubMed] [Google Scholar]
- Riddle V. G., Dubrow R., Pardee A. B. Changes in the synthesis of actin and other cell proteins after stimulation of serum-arrested cells. Proc Natl Acad Sci U S A. 1979 Mar;76(3):1298–1302. doi: 10.1073/pnas.76.3.1298. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Riddle V. G., Pardee A. B. Quiescent cells but not cycling cells exhibit enhanced actin synthesis before they synthesize DNA. J Cell Physiol. 1980 Apr;103(1):11–15. doi: 10.1002/jcp.1041030103. [DOI] [PubMed] [Google Scholar]
- Spiegelman B. M., Farmer S. R. Decreases in tubulin and actin gene expression prior to morphological differentiation of 3T3 adipocytes. Cell. 1982 May;29(1):53–60. doi: 10.1016/0092-8674(82)90089-7. [DOI] [PubMed] [Google Scholar]
- Thomas P. S. Hybridization of denatured RNA and small DNA fragments transferred to nitrocellulose. Proc Natl Acad Sci U S A. 1980 Sep;77(9):5201–5205. doi: 10.1073/pnas.77.9.5201. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Wittelsberger S. C., Kleene K., Penman S. Progressive loss of shape-responsive metabolic controls in cells with increasingly transformed phenotype. Cell. 1981 Jun;24(3):859–866. doi: 10.1016/0092-8674(81)90111-2. [DOI] [PubMed] [Google Scholar]