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

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 similar to 19 kDa 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. (C) 2010 Elsevier B.V. All rights reserved.