Transforming growth factor‐β regulates the splicing pattern of fibronectin messenger RNA precursor

Abstract

Fibronectin (FN) polymorphism is caused by alternative splicing patterns in at least three regions (ED-A, ED-B and IIICS) of the primary transcript of a single gene. Using monoclonal antibodies, we previously demonstrated that transforming growth factor-β (TGF-β) preferentially increases the accumulation of the FN isoforms containing the ED-A sequence in cultured normal human fibroblasts [Balza et al., (1988) FEBS Lett. 228, 42-44]. To determine the basis of this effect, we have examined through S1 nuclease analysis, the levels of ED-A- and ED-B-containing mRNAs in cultured normal human skin flbroblasts before and after TGF-β treatment. These experiments have shown that TGF-β increases the relative amount of m-RNA for ED-A- and ED-B-containing FN isoforms. These data demonstrate that a growth factor may regulate the splicing pattern of a pre-mRNA.