Selective induction of stalk-cell-specific proteins in Dictyostelium.
We compared the proteins synthesized and accumulated by Dictyostelium discoideum amoebae in response to the morphogenetic factor termed differentiation-inducing factor (DIF) to assess the proposed ability of DIF to regulate the choice of differentiation pathway. When amoebae of a mutant strain with low endogenous DIF levels were given DIF, they dramatically increased the expression of 21 of 23 proteins preferentially found in stalk cells, but drastically repressed 4 major spore-specific proteins. Most of the induced proteins were also expressed in amoebae of a developmentally competent strain developing at low cell densities and exposed to DIF, low extracellular pH, or the proton pump inhibitor diethylstilbestrol; this suggests that an intracellular acidification may be a key part of the mechanism of DIF action. We conclude from the similar morphology and extensive homology of proteins of DIF-induced and stalk cells that most stalk-pathway functions are DIF dependent.
D000818:Animals; D004023:Dictyostelium / Q000378:metabolism*; D004586:Electrophoresis; D006023:Glycoproteins / Q000494:pharmacology; D006131:Growth Inhibitors; D006863:Hydrogen-Ion Concentration; D015850:Interleukin-6; D053605:Leukemia Inhibitory Factor; D008222:Lymphokines; D014176:Protein Biosynthesis; D013997:Time Factors
D006023:Glycoproteins; D006131:Growth Inhibitors; D015850:Interleukin-6; D053605:Leukemia Inhibitory Factor; D008222:Lymphokines