| Abstract [eng] |
In this study indole-3-acetic acid (IAA or auxin) recognizing and specifically binding proteins – ABP localization in cell were investigated. For the first time, the localization and functioning of ABP in cell organelles – chloroplasts and mitochondria – was demonstrated in the level of organelles, sub-compartments and proteins. Functioning of two different ABP was established in chloroplasts: one ABP was localized in stroma, another ABP – in membranes. ABP functioning in mitochondria was localized in membranes. It was disclosed, that IAA and ABPs interaction in this organelles was biologically significant – only physiologically active compounds competed for IAA binding to ABPs sites. Chloroplast and mitochondria ABPs were distinguished in high auxin-binding activity, but had a rather low affinity for IAA ligand and possessed a large number of binding sites. IAA-ABP complexes forming in these organelles were different according to their main characteristics. They differed from IAA-ABP complexes forming in kidney bean hypocotyls or wheat coleoptiles cells, responding to IAA by elongation growth, in cytosol and plasmalemma compartments as well as from complexes forming with ABP1 and TIR1. Therefore a presumption was made, that the structure of IAA molecule binding sites and the function of forming IAA-ABP complexes might be different. |
