Both cell substratum regulation and hormonal regulation of milk protein gene expression are exerted primarily at the posttranscriptional level

Journal Article · Mon Aug 01 04:00:00 EDT 1988 · Mol. Cell. Biol.; (United States)

DOI:https://doi.org/10.1128/MCB.8.8.3183· OSTI ID:6737096

Eisenstein, R S; Rosen, J M

The mechanism by which individual peptide and steroid hormones and cell-substratum interactions regulate milk protein gene expression has been studied in the COMMA-D mammary epithelial cell line. In the presence of insulin, hydrocortisone, and prolactin, growth of COMMA-D cells on floating collagen gels in comparison with that on a plastic substratum resulted in a 2.5- to 3-fold increase in the relative rate of ..beta..-casein gene transcription but a 37-fold increase in ..beta..-casein mRNA accumulation. In contrast, whey acidic protein gene transcription was constitutive in COMMA-D cells grown on either substratum, but its mRNA was unstable and little intact mature mRNA was detected. Culturing COMMA-D cells on collagen also promoted increased expression of other genes expressed in differentiated mammary epithelial cells, including those encoding ..cap alpha..- and ..gamma..-casein, transferrin, malic enzyme, and phosphoenolpyruvate carboxykinase but decreased the expression of actin and histone genes. Using COMMA-D cells, the authors defined further the role of individual hormones in influencing ..beta..-casein gene transcription. With insulin alone, a basal level of ..beta..-casein gene transcription was detected in COMMA-D cells grown on floating collagen gels. Addition of prolactin but not hydrocortisone resulted in a 2.5- to 3.0-fold increase in ..beta..-casein gene transcription, but both hormones were required to elicit the maximal 73-fold induction in mRNA accumulation. The posttranscriptional effect of hormones on casein mRNA accummulation preceded any detectable changes in the relative rate of transcription. Thus, regulation by both hormones and cell substratum of casein gene expression is exerted primarily at the post transcriptional level.

• Research Organization: Dept. of Applied Biological Sciences, Building 56-224, Massachusetts Institute of Technology, Cambridge, MA (US)
• OSTI ID: 6737096
• Journal Information: Mol. Cell. Biol.; (United States), Journal Name: Mol. Cell. Biol.; (United States) Vol. 8:8; ISSN MCEBD
• Country of Publication: United States
• Language: English

Related Subjects

550200* -- Biochemistry
550800 -- Morphology
59 BASIC BIOLOGICAL SCIENCES
ACTIN
ADRENAL HORMONES
ANIMAL TISSUES
BIOLOGICAL FUNCTIONS
BODY
CARBOXYLIC ACIDS
CASEIN
CELL CULTURES
CELL DIFFERENTIATION
CORTICOSTEROIDS
ENZYMES
EPITHELIUM
FUNCTIONS
GENE REGULATION
GENES
GLOBULINS
GLOBULINS-BETA
GLUCOCORTICOIDS
HISTONES
HORMONES
HYDROCORTISONE
HYDROXY COMPOUNDS
KETO ACIDS
KETONES
MESSENGER-RNA
METALLOPROTEINS
MOLECULAR BIOLOGY
NUCLEIC ACIDS
NUCLEOPROTEINS
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC PHOSPHORUS COMPOUNDS
PEPTIDE HORMONES
PHENOTYPE
PHOSPHORUS-GROUP TRANSFERASES
PHOSPHOTRANSFERASES
POST-TRANSLATION MODIFICATION
PREGNANES
PROTEINS
PYRUVIC ACID
RNA
STEROIDS
TISSUES
TRANSCRIPTION
TRANSFERASES
TRANSFERRIN