Modulation of secreted proteins of mouse mammary epithelial cells by the collagenous substrata

Journal Article · Sun Jan 01 04:00:00 EST 1984 · J. Cell Biol.; (United States)

DOI:https://doi.org/10.1083/jcb.98.1.146· OSTI ID:5906222

Lee, E Y.H.; Parry, G; Bissell, M J

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. In this paper we show: (a) Cells on floating collagen gels secrete not only ..gamma..-casein but also ..cap alpha../sub 1/-, ..cap alpha../sub 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. 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.

• Research Organization: Lawrence Berkeley Lab., CA
• DOE Contract Number: AC03-76SF00098
• OSTI ID: 5906222
• Journal Information: J. Cell Biol.; (United States), Journal Name: J. Cell Biol.; (United States) Vol. 98:1; ISSN JCLBA
• Country of Publication: United States
• Language: English

Related Subjects

550200 -- Biochemistry
550300* -- Cytology
59 BASIC BIOLOGICAL SCIENCES
ALBUMINS
ANIMAL TISSUES
ANIMALS
BIOCHEMISTRY
BIOLOGICAL MATERIALS
BIOSYNTHESIS
BODY
BODY FLUIDS
CELL CULTURES
CHEMISTRY
COLLAGEN
CULTURE MEDIA
CYTOLOGICAL TECHNIQUES
EPITHELIUM
FOOD
GLANDS
GLOBULINS
GLOBULINS-BETA
INDUSTRIAL WASTES
MAMMALS
MAMMARY GLANDS
MATERIALS
METALLOPROTEINS
MICE
MILK
ORGANIC COMPOUNDS
ORGANS
PROTEINS
RODENTS
SCLEROPROTEINS
SUBSTRATES
SYNTHESIS
TISSUES
TRANSFERRIN
VERTEBRATES
WASTES
WHEY