Format

Send to

Choose Destination
See comment in PubMed Commons below
J Biol Chem. 1998 Apr 17;273(16):9495-500.

Regulation of mammary differentiation by extracellular matrix involves protein-tyrosine phosphatases.

Author information

  • 1School of Biological Sciences, University of Manchester, 3.239 Stopford Building, Oxford Road, Manchester, M13 9PT, United Kingdom.

Abstract

Extracellular matrix and growth factors cooperate to regulate signaling pathways and gene transcription in adherent cells. However, the mechanism of extracellular matrix signaling is poorly defined. In mammary gland, the expression of milk protein genes is controlled by cross-talk between signals derived from the basement membrane protein, laminin, and the lactogenic hormone, prolactin. Signals from basement membrane are transduced by beta1 integrins and are required for prolactin to activate DNA binding of the milk protein gene transcription factor, Stat5. Here we show that basement membrane is necessary for tyrosine phosphorylation of the prolactin receptor and thus directly affects cytokine signaling and differentiation at the level of the plasma membrane. Prolactin does not induce tyrosine phosphorylation of its receptor, Jak2, or Stat5 in nondifferentiated breast epithelia cultured on collagen I, and we show that this is due to a vanadate-sensitive activity that inhibits the prolactin pathway. We suggest that protein-tyrosine phosphatases are novel targets for regulation by extracellular matrix and in mammary cells represent an additional control to the requirement of integrins for milk protein production.

PMID:
9545277
[PubMed - indexed for MEDLINE]
Free full text

LinkOut - more resources

Full Text Sources

Other Literature Sources

PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for HighWire
    Loading ...
    Support Center