Peculiarities of the formation of indole-3-acetic acid – protein complexes in yeast Saccharomyces cerevisiae plasmalemma

Anotacija

The aim of our work was to elucidate whether the yeast Saccharomyces cerevisiae can receive the phytohormone IAA signal in the plasmalemma and to transduce it to the nucleus, eliciting changes in RNA synthesis peculiar also to the cells of the higher plants (wheat coleoptiles). IAA has been found able to form complexes with proteins in yeast strain α’1-1JA-R+N cell plasmalemma, which enhanced RNApolymerase II activity in the system of isolated nuclei of the same yeast strain cells. However, in the plasmalemma of this yeast strain cells one type of IAA–protein complexes of a relatively low affinity has been found, and according to fixed characteristics of IAA–protein complex formation in yeast cell plasmalemma in the Scatchard co-ordinates (Ka » 1361.034; Kd ≈7.35 • 10–4 M; n ≈2.07 • 10–8 mol/μg protein) these complexes cannot be considered receptory. Keywords: IAA–protein complexes, yeast, plasmalemma