Baker's yeast S. cerevisiae being a genetically and functionally well-defined and easily handled eukaryotic cell is an attractive host for production of mammalian proteins and good tool for analysis of proteins misfolding and searching for therapeutic agents affecting amyloid aggregation and propagation. Fusion proteins Aβ-GFP and PrP-GFP overexpressed in yeast form oligomeres and high-weight aggregates as opposed to cells expressing bare GFP. Cytoplasmic localization of large fluorescent aggregates of the fusion proteins has been proved by staining with fluorescent dyes for particular cellular compartments. Fluorescence recovery after photobleaching (FRAP) examination of PrP-GFP fluorescent fibrils and visible clumps of Aβ-GFP in living cells have revealed significant portion of immobile fraction in the aggregates, which reflects tight stable interactions between individual molecules. These data are well agreed with high resistance of the fusion proteins to SDS treatment as well as yeast proteases and proteinase K digestion. The results suggest amyloid nature of PrP-GFP and Aβ-GFP aggregates in yeast making the system useful for analysis of factors affecting amyloidogenesis. This work is supported by Fogarty (TW006965-01A1), Ministry of Education and Science RF (PHII.2.2.2.3.10047) and CRDF (BRHE Y4-B-12-04).