Abstract
It has been shown previously that cultures of mouse mammary epithelial cells retain their characteristic morphology and their ability to produce gamma-casein, a member of the casein gene family, only if they are maintained on floating collagen gels (Emerman, J.T., and D.R. Pitelka, 1977, In Vitro, 13:316-328). In this paper we show: (a) Cells on floating collagen gels secrete not only gamma-casein but also alpha 1-, alpha 2-, and beta-caseins. These are not secreted by cells on plastic and are secreted to only a very limited extent by cells on attached collagen gels. (b) The floating collagen gel regulates at the level of synthesis and/or stabilization of the caseins rather than at the level of secretion alone. Contraction of the floating gel is important in that cells cultured on floating glutaraldehyde cross- linked gels do not secrete any of the caseins. (c) The secretion of an 80,000-mol-wt protein, most probably transferrin, and a 67,000-mol-wt protein, probably butyrophilin, a major protein of the milk fat globule membrane are partially modulated by substrata. However, in contrast to the caseins, these are always detectable in media from cells cultured on plastic and attached gels. (d) Whey acidic protein, a major whey protein, is actively secreted by freshly isolated cells but is secreted in extremely limited quantities in cultured cells regardless of the nature of the substratum used. alpha-Lactalbumin secretion is also decreased significantly in cultured cells. (e) A previously unreported set of proteins, which may be minor milk proteins, are prominently secreted by the mammary cells on all substrata tested. We conclude that while the substratum profoundly influences the secretion of the caseins, it does not regulate the expression of every milk-specific protein in the same way. The mechanistic implications of these findings are discussed.
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Selected References
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- Bartley J. C., Emerman J. T., Bissell M. J. Metabolic cooperativity between epithelial cells and adipocytes of mice. Am J Physiol. 1981 Nov;241(5):C204–C208. doi: 10.1152/ajpcell.1981.241.5.C204. [DOI] [PubMed] [Google Scholar]
- Bissell M. J., Hall H. G., Parry G. How does the extracellular matrix direct gene expression? J Theor Biol. 1982 Nov 7;99(1):31–68. doi: 10.1016/0022-5193(82)90388-5. [DOI] [PubMed] [Google Scholar]
- Cleveland D. W., Fischer S. G., Kirschner M. W., Laemmli U. K. Peptide mapping by limited proteolysis in sodium dodecyl sulfate and analysis by gel electrophoresis. J Biol Chem. 1977 Feb 10;252(3):1102–1106. [PubMed] [Google Scholar]
- Emerman J. T., Bartley J. C., Bissell M. J. Glucose metabolite patterns as markers of functional differentiation in freshly isolated and cultured mouse mammary epithelial cells. Exp Cell Res. 1981 Jul;134(1):241–250. doi: 10.1016/0014-4827(81)90481-x. [DOI] [PubMed] [Google Scholar]
- Emerman J. T., Bartley J. C., Bissell M. J. Interrelationship of glycogen metabolism and lactose synthesis in mammary epithelial cells of mice. Biochem J. 1980 Nov 15;192(2):695–702. doi: 10.1042/bj1920695. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Emerman J. T., Enami J., Pitelka D. R., Nandi S. Hormonal effects on intracellular and secreted casein in cultures of mouse mammary epithelial cells on floating collagen membranes. Proc Natl Acad Sci U S A. 1977 Oct;74(10):4466–4470. doi: 10.1073/pnas.74.10.4466. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Emerman J. T., Pitelka D. R. Maintenance and induction of morphological differentiation in dissociated mammary epithelium on floating collagen membranes. In Vitro. 1977 May;13(5):316–328. doi: 10.1007/BF02616178. [DOI] [PubMed] [Google Scholar]
- Enami J., Nandi S. A sensitive radioimmunoassay for a component of mouse casein. J Immunol Methods. 1977;18(3-4):235–244. doi: 10.1016/0022-1759(77)90177-6. [DOI] [PubMed] [Google Scholar]
- Franke W. W., Heid H. W., Grund C., Winter S., Freudenstein C., Schmid E., Jarasch E. D., Keenan T. W. Antibodies to the major insoluble milk fat globule membrane-associated protein: specific location in apical regions of lactating epithelial cells. J Cell Biol. 1981 Jun;89(3):485–494. doi: 10.1083/jcb.89.3.485. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Green M. R., Pastewka J. V. Characterization of major milk proteins from BALB/c and C3H mice. J Dairy Sci. 1976 Feb;59(2):207–215. doi: 10.3168/jds.S0022-0302(76)84186-0. [DOI] [PubMed] [Google Scholar]
- Green M. R., Pastewka J. V. Molecular weights of three mouse milk caseins by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and kappa-like characteristics of a fourth casein. J Dairy Sci. 1976 Oct;59(10):1738–1745. doi: 10.3168/jds.S0022-0302(76)84431-1. [DOI] [PubMed] [Google Scholar]
- Hennighausen L. G., Sippel A. E. Characterization and cloning of the mRNAs specific for the lactating mouse mammary gland. Eur J Biochem. 1982 Jun 15;125(1):131–141. doi: 10.1111/j.1432-1033.1982.tb06660.x. [DOI] [PubMed] [Google Scholar]
- Hinegardner R. T. An improved fluorometric assay for DNA. Anal Biochem. 1971 Jan;39(1):197–201. doi: 10.1016/0003-2697(71)90476-3. [DOI] [PubMed] [Google Scholar]
- Hobbs A. A., Richards D. A., Kessler D. J., Rosen J. M. Complex hormonal regulation of rat casein gene expression. J Biol Chem. 1982 Apr 10;257(7):3598–3605. [PubMed] [Google Scholar]
- LARSON B. L., GILLESPIE D. C. Origin of the major specific proteins in milk. J Biol Chem. 1957 Aug;227(2):565–573. [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]
- Lee W. H., Bister K., Moscovici C., Duesberg P. H. Temperature-sensitive mutants of Fujinami sarcoma virus: tumorigenicity and reversible phosphorylation of the transforming p140 protein. J Virol. 1981 Jun;38(3):1064–1076. doi: 10.1128/jvi.38.3.1064-1076.1981. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Matusik R. J., Rosen J. M. Prolactin induction of casein mRNA in organ culture. A model system for studying peptide hormone regulation of gene expression. J Biol Chem. 1978 Apr 10;253(7):2343–2347. [PubMed] [Google Scholar]
- McKenzie R. M., Larson B. L. Purification and partial characterization of a unique group of phosphoproteins from rat milk whey. J Dairy Sci. 1978 Jun;61(6):723–728. doi: 10.3168/jds.S0022-0302(78)83639-X. [DOI] [PubMed] [Google Scholar]
- Mehta N. M., Ganguly N., Ganguly R., Banerjee M. R. Hormonal modulation of the casein gene expression in a mammogenesis-lactogenesis culture model of the whole mammary gland of the mouse. J Biol Chem. 1980 May 25;255(10):4430–4434. [PubMed] [Google Scholar]
- Michalopoulos G., Pitot H. C. Primary culture of parenchymal liver cells on collagen membranes. Morphological and biochemical observations. Exp Cell Res. 1975 Aug;94(1):70–78. doi: 10.1016/0014-4827(75)90532-7. [DOI] [PubMed] [Google Scholar]
- Nagamatsu Y., Oka T. Purification and characterization of mouse alpha-lactalbumin and preparation of its antibody. Biochem J. 1980 Jan 1;185(1):227–237. doi: 10.1042/bj1850227. [DOI] [PMC free article] [PubMed] [Google Scholar]
- O'Farrell P. Z., Goodman H. M., O'Farrell P. H. High resolution two-dimensional electrophoresis of basic as well as acidic proteins. Cell. 1977 Dec;12(4):1133–1141. doi: 10.1016/0092-8674(77)90176-3. [DOI] [PubMed] [Google Scholar]
- Ono M., Oka T. The differential actions of cortisol on the accumulation of alpha-lactalbumin and casein in midpregnant mouse mammary gland in culture. Cell. 1980 Feb;19(2):473–480. doi: 10.1016/0092-8674(80)90522-x. [DOI] [PubMed] [Google Scholar]
- Piletz J. E., Heinlen M., Ganschow R. E. Biochemical characterization of a novel whey protein from murine milk. J Biol Chem. 1981 Nov 25;256(22):11509–11516. [PubMed] [Google Scholar]
- Razooki Hasan H., White D. A., Mayer R. J. Extensive destruction of newly synthesized casein in mammary explants in organ culture. Biochem J. 1982 Jan 15;202(1):133–138. doi: 10.1042/bj2020133. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Shannon J. M., Pitelka D. R. The influence of cell shape on the induction of functional differentiation in mouse mammary cells in vitro. In Vitro. 1981 Nov;17(11):1016–1028. doi: 10.1007/BF02618428. [DOI] [PubMed] [Google Scholar]
- Towbin H., Staehelin T., Gordon J. Electrophoretic transfer of proteins from polyacrylamide gels to nitrocellulose sheets: procedure and some applications. Proc Natl Acad Sci U S A. 1979 Sep;76(9):4350–4354. doi: 10.1073/pnas.76.9.4350. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Wicha M. S., Lowrie G., Kohn E., Bagavandoss P., Mahn T. Extracellular matrix promotes mammary epithelial growth and differentiation in vitro. Proc Natl Acad Sci U S A. 1982 May;79(10):3213–3217. doi: 10.1073/pnas.79.10.3213. [DOI] [PMC free article] [PubMed] [Google Scholar]