Transforming growth factors produced by retrovirus-transformed rodent fibroblasts and human melanoma cells: amino acid sequence homology with epidermal growth factor
Transforming growth factors (TGFs) were purified from serum-free medium conditioned by retrovirus-transformed Fisher rat embryo fibroblasts, mouse 3T3 cells, and two human melanoma cell lines. The purification of each TGF was monitored in a radioreceptor assay based on receptor crossreactivity with mouse submaxillary gland epidermal growth factor (mEGF) and was achieved by gel permeation chromatography of the acid-soluble TGF-containing activity, followed by reverse-phase high-pressure liquid chromatography with sequential use of acetonitrile and 1-propanol in the presence of aqueous trifluoroacetic acid. The amino-terminal sequences of rat, mouse, and human TGFs were determined. Extensive sequence homology was found among TGF polypeptides from different species and cell types. Alignment of the amino acid sequences of rat TGF, mEGF, and human urogastrone (hEGF) reveals statistically significant sequence homology. The reported results suggest that TGFs that compete for binding to the cellular EGF receptor and EGF may have evolved from a common progenitor.
Additional Information© 1983 by the National Academy of Sciences. Contributed by Leroy E. Hood, May 2, 1983. We are grateful to Dr. Winona C. Barker for the statistical analyses, to John P. Bordonaro and Jane Ranchalis for able technical assistance, to Dolores Winterstein and E. Siobhan McCormack for preparing conditioned medium, and to Virginia Frye for typing this manuscript. The publication costs of this article were defrayed in part by page charge payment. This article must therefore be hereby marked "advertisement" in accordance with 18 U.S.C. §1734 solely to indicate this fact.
Published - MARpnas83.pdf