Recombinant expression and characterization of human activin A.
Activin, which stimulates the secretion of FSH from anterior pituitary cells, is a dimer of the beta-subunits of inhibin. Two species of activin (A and AB) have been purified from ovarian follicular fluid and characterized. We have been able to biosynthetically produce recombinant human activin A by constructing stable cell lines expressing the mRNA for the beta A subunit of human inhibin. These cell lines secreted a 24 kilodalton beta A dimer which stimulated FSH secretion in cultured pituitary cells. The ability of this protein to stimulate FSH secretion was sensitive to reduction of disulfide bonds, exhibited a slow onset of action, and was blocked by actinomycin D. In addition, recombinant activin A stimulated hemoglobin accumulation in K562 cells. These data show that recombinant activin A has the biochemical properties and biological activities that have been ascribed to native activin A. In addition, these results provide an independent confirmation, and thereby a final proof, of the structure and function of activin.
Schwall
R H
RH
Department of Developmental Biology, Genentech, Inc., South San Francisco, California 94080.
Nikolics
K
K
Szonyi
E
E
Gorman
C
C
Mason
A J
AJ
D028341:Activins; D000595:Amino Acid Sequence; D005786:Gene Expression Regulation; D006801:Humans; D007265:Inhibins / Q000235:genetics*; D008969:Molecular Sequence Data; D011995:Recombination, Genetic
D028341:Activins; D007265:Inhibins