Tenascin

Tenascins are extracellular matrix glycoproteins. They are abundant in the extracellular matrix of developing vertebrate embryos and they reappear around healing wounds and in the stroma of some tumors.

Types

There are four members of the tenascin gene family: tenascin-C, tenascin-R, tenascin-X and tenascin-W.

The basic structure is 14 EGF-like repeats towards the N-terminal end, and 8 or more fibronectin-III domains which vary upon species and variant.

Tenascin-C is the most intensly studied member of the family. It has anti-adhesive properties, causing cells in tissue culture to become rounded after it is added to the medium. One mechanism to explain this may come from its ability to bind to the extracellular matrix glycoprotein fibronectin and block fibronectin's interactions with specific syndecans. The expression of tenascin-C in the stroma of certain tumors is associated with a poor prognosis.