© 1999 by CRC Press LLC
The interactions of cells with pericellular fibronectin matrix play critical roles in
cell adhesion, migration, growth, survival, differentiation, and gene expression.
At least two components contribute specificity to this important recognition sys-
tem. Responsive cells must express suitable receptors recognizing pericellular
fibronectin matrix. In addition, the assembly of pericellular fibronectin matrix
must be properly controlled. Our understanding of the molecular mechanism by
which cells control pericellular fibronectin matrix assembly, although still incom-
plete, has advanced significantly over the last several years. This was achieved
through a combination of biochemical, cell biological, and genetic experimental
approaches. In this chapter, I will first discuss, briefly, some of the recent findings
on the signaling mechanisms involved in the cellular control of fibronectin matrix
assembly, primarily focusing on the roles of integrin signaling. For detailed dis-
cussion of fibronectin matrix assembly, readers are referred to several excellent
review articles that have been previously published.
Next, I will describe two
basic experimental methods for analyzing fibronectin matrix assembly, and discuss
some of the major technical considerations in designing experiments aimed at
evaluating cellular activity of fibronectin matrix assembly. Due to space limitation,
many other useful methods could not be included; readers are encouraged to
consult the original publications listed in the reference sections of this chapter
and other review articles.
Fibronectins are modular, multidomain glycoproteins of approximately
500,000 daltons consisting of repeating homologies of three types.
organogenesis, fibronectins are major constituents of the extracellular matrix.
Inactivation of the mouse fibronectin gene causes early embryonic lethality,
demonstrating that fibronectin matrix is indispensable for vertebrate embryogen-
esis. In adult mammals, most fibronectin is synthesized by the liver and exists
primarily as a soluble plasma protein present at high concentration (about