Molecular cloning, in vitro expression and bioactivity of rabbit transforming growth factor-beta receptor type II (rTGF- beta RII)

摘要

Transforming growth factor-beta receptor II (TGF- beta RII) is an attractive target for anti-scarring therapy in wound healing because it attenuates excessive TGF- beta which has pleiotropic effects on the immune system. In the present study, the cDNA of rabbit TGF- beta RII (rTGF- beta RII) was amplified from rabbit peripheral blood by RT-PCR. The open reading frame of rTGF- beta RII encodes a protein consisting of 567 amino acids, which contains a predicted transmembrane domain and a Serine/Threonine protein kinase domain similar to other identified mammalian TGF- beta RIIs. The amino acid sequences of the biologically active, soluble rTGF- beta RII and mouse, rat, human and chicken counterparts are 81%, 81%, 89% and 61%, respectively, identical. Recombinant soluble rTGF- beta RII (rsTGF- beta RII) fused with His tag was efficiently expressed in Escherichia coli BL21 (DE3) expression host strain. This fusion protein's molecular weight of a arrow right 419kDa was identified by SDS-PAGE and Western blotting. In vitro, purified rsTGF- beta RII was able to inhibit the proliferation of keloid rabbit fibroblasts and decrease the level of collagen. These findings indicate that rTGF- beta RII plays an important role in inhibiting the proliferation of keloid rabbit fibroblasts and provides the basis for investigations on the role of TGF- beta RII in this important domestic species.