Extracellular matrix transduction

The integrins define attachment points for the extracellular matrix and for contact with neighboring cells, and they are involved in signal transduction into the cell interior. With these functions, the integrins are involved in regulation of embryonal... 

Receptors (adhesion receptors) that interact with macromolecular components of the extracellular matrix (such as collagen) and convey to the cytoskeletal system instructions on cell migration or adherence to the matrix. Integrins (discussed in Chapter 10) illustrate this general type of transduction mechanism. 

Figure 1. The muscle dystrophin-glycoprotein complex. The dystrophin-glycoprotein complex normally spans the plasma membrane of the skeletal muscle cell and may stabilize the sarcolemma and cytoskeleton to allow force transduction between the intracellular cytoskeleton (F-actin filaments) and the extracellular matrix. The molecules indicated are core components of the dystrophin-glycoprotein complex. Laminin 2 is the predominant laminin isoform in skeletal muscle basement membranes. Modified from McNeil and Steinhardt (2003)...

Mechanosensing is used to describe the process by which cells sense mechanical forces. Mechanochemical transduction is the phrase that is used to try to describe the biological processes by which external forces such as gravity influence the biochemical and genetic responses of cells and tissues. Specifically, these responses include stimulation of cell proliferation or apoptosis (death) and synthesis or catabolism of components of the extracellular matrix. These processes cause either increases in chemical energy (conversion of amino acids or other small molecules into macromolecules) or decreases in chemical energy (depolymerization of macromolecules). 

Juliano RE, Haskill S. Signa. transduction from the extracellular matrix. J. Cell. Biol. 1993 120 577-585. 

A modular architecture is no particular hallmark of enzymes, the highest degree of modularity is typically observed in structural proteins of the extracellular matrix and in proteins involved in intracellular signal transduction. Nevertheless, there are a number of modular enzymes including some which are of interest for biocatalytic applications. 

---