Cell-type Specific Recognition of RGD- and Non-RGD-containing Cell Binding Domains in Fibrillin-1

doi:10.1074/jbc.271.9.4916

Cell-type Specific Recognition of RGD- and Non-RGD-containing Cell Binding Domains in Fibrillin-1 (*)

From the (1)Departments of Cell Biology and Physiology and
(2)Medicine, Washington University School of Medicine, St. Louis, Missouri 63110,
(3)Department of Immunology, Scripps Research Institute, La Jolla, California 92037,
(4)Brookdale Center for Molecular Biology, Mt. Sinai School of Medicine, New York, New York 10029, and
(5)School of Dental Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104

⁽ To whom correspondence should be addressed:
Dept. of Cell Biology and Physiology, Washington University School of Medicine, Box 8228, 660 South Euclid Ave., St. Louis, MO 63110.
Tel.: 314-362-2254; Fax: 314-362-2252.

Abstract

The fibrillins are large glycoprotein components of 10-nm microfibrils found in the extracellular matrix of most tissues. Microfibrils play a role in elastic fiber assembly and serve to link cells to elastic fibers in the extracellular matrix. To determine whether fibrillin-1 specifically interacts with receptors on cells from fibrillin-rich tissues, we evaluated whether two cell types that produce different types of fibrillin can adhere to purified fibrillin-1 in cell adhesion assays. Our results indicate that both cell types attach and spread on fibrillin-1 and that the RGD sequence in the fourth 8-cysteine motif mediates this interaction. Fibroblast attachment to fibrillin-1 was sensitive to inhibition by antibodies to the αvβ3 receptor and by peptides encoding the RGD sequence in fibrillin-1 and the second RGD sequence in fibrillin-2. In contrast, adhesion of auricular chondroblasts to fibrillin-1 was only partially inhibited by these reagents, suggesting that some cell types recognize a second, non-RGD binding site within the fibrillin molecule. These findings confirm and extend ultrastructural studies that suggest a direct interaction between microfibrils and the cell surface and provide a functional explanation for how this association occurs.

Footnotes

↵* This work was supported by National Institutes of Health Grants HL-26499 and HL-41926 (to R. P. M.), AR-41474 (to J. R.), CA50286 and CA45726 (to D. A. C.), and AR42044 (to F. R.). This is article 165 from the Brookdale Center for Molecular Biology. 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:

MAGP

microfibril-associated glycoprotein

FCL

fetal bovine ligamentum nuchae

FBC

fetal bovine auricular cartilage

LTBP-2

latent transforming growth factor-β-binding protein-2

DMEM

Dulbecco's modified Eagle's medium

BSA

bovine serum albumin.
↵²H. Sakamoto, T. Broekelmann, and R. P. Mecham, unpublished observations.
- Received September 21, 1995.
- Revision received November 24, 1995.