Control of Integrin Expression by Extracellular Matrix

doi:10.1074/jbc.270.45.26794

Control of Integrin Expression by Extracellular Matrix (*)

From the School of Biological Sciences, University of Manchester, Manchester M13 9PT, United Kingdom

^§ Wellcome Senior Research Fellow in Basic Biomedical Science. To whom correspondence should be addressed:
School of Biological Sciences, University of Manchester, 3.239 Stopford Bldg., Manchester M13 9PT, UK
. Tel.: 44-161-275-5626; Fax: 44-161-275-3915.

Abstract

Integrin-mediated interactions between cells and the extracellular matrix play a fundamental role in the development and function of a variety of tissues by triggering intracellular signals that regulate gene expression. In this study, mouse mammary epithelial cells plated on tissue culture plastic were shown to dramatically up-regulate the steady state levels of mRNA encoding the α, α, α, α, α, α, α, and β integrin subunits, in contrast to cells cultured on a basement membrane matrix or cells in vivo. This pattern of expression was also observed in a mouse mammary epithelial strain, CID-9 and in other mouse cell lines such as MMTE cells and K1735-M2 melanoma cells. The control of integrin expression was mediated at different levels in different cell types. In K1735-M2 cells, transcription of the β integrin gene was influenced by the substratum, although the levels of integrin protein remained similar. In mammary epithelial cells, the rates of β integrin gene transcription were similar, but mRNA and protein levels were higher in cells cultured on plastic than those on basement membrane. For both cell types, the rate of integrin protein turnover was nearly identical in cells cultured on either substratum. Our results demonstrate that extracellular matrix controls the expression of β integrin subunits and that this regulation is exerted at both transcriptional and post-transcriptional levels.

Footnotes

↵* The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore by hereby marked “advertisement” in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.
↵¹ The abbreviations used are:

ECM

extracellular matrix

mAb

monoclonal antibody

DMEM

Dulbecco's modified Eagle's medium

FCS

fetal calf serum

CAT

chloramphenicol acetyltransferase

PAGE

polyacrylamide gel electrophoresis

TGF

transforming growth factor

EHS

Engelbreth-Holm-Swarm sarcoma

bp

base pair(s)

kb

kilobase pair(s).
↵² T. G. Burdon, C. J. Watson, and C. H. Streuli, unpublished data.
↵³ S. Pullan, J. Wilson, A. Metcalfe, G. Edwards, N. Goberdhan, J. Tilly, J. A. Hickman, C. Dive, and C. H. Streuli, manuscript submitted for publication.
- Received October 19, 1994.
- Revision received August 23, 1995.