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A specific DIF binding protein in Dictyostelium.
Author(s) -
Insall R.,
Kay R. R.
Publication year - 1990
Publication title -
the embo journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 7.484
H-Index - 392
eISSN - 1460-2075
pISSN - 0261-4189
DOI - 10.1002/j.1460-2075.1990.tb07532.x
Subject(s) - biology , dictyostelium , binding site , microbiology and biotechnology , gene , biochemistry
Differentiation Inducing Factor (DIF‐1), a small chlorinated organic molecule which is produced during Dictyostelium development, is believed to be the morphogen that controls the stalk‐specific pathway of differentiation. We describe the identification and characterization of a protease‐sensitive activity from cell lysates which binds tritiated DIF‐1 with the properties expected of a DIF receptor. Scatchard and linear subtraction plots show a single class of binding sites, of high affinity (Kd = 1.8 nM) and low abundance (1100 sites/cell). The activity elutes from heparin‐agarose as a single peak. Various DIF‐1 analogues compete for binding in proportion to their activities in a stalk cell differentiation bioassay. The amount of binding activity is developmentally regulated, peaking shortly before the appearance of the prestalk‐prespore pattern and before the developmental rise in DIF concentration; the rise occurs at the same time that prestalk‐specific genes become DIF inducible. Addition of cyclic AMP to aggregated cells, which induces post‐aggregative gene expression in general, also induces the binding activity.