Ricerc@Sapienza

The class of Cullin–RING E3 ligases (CRLs) selectively ubiquitinate a large portion of proteins targeted for proteolysis by the 26S proteasome. Before degradation, ubiquitin molecules are removed from their conjugated proteins by deubiquitinating enzymes, a handful of which are associated with the proteasome. The CRL activity is triggered by modification of the Cullin subunit with the ubiquitin-like protein, NEDD8 (also known as Rub1 in Saccharomyces cerevisiae). Cullin modification is then reversed by hydrolytic action of the COP9 signalosome (CSN).

Elucidating the biology of yeast in its full complexity has major implications for science, medicine and industry. One of the most critical processes determining yeast life and physiology is cel- lular demise. However, the investigation of yeast cell death is a relatively young field, and a widely accepted set of concepts and terms is still missing. Here, we propose unified criteria for the defi- nition of accidental, regulated, and programmed forms of cell death in yeast based on a series of morphological and biochemical criteria.

One of the earliest domesticated organisms is perhaps the eukaryote microorganism known as Saccharomyces cerevisiae, or more simply “the yeast”. Its decisive role in triggering fermentation as a process useful for agricultural products preservation and transformation into consumable food, though known from the Palaeolithic in the ancient Near East, became decisive in the Neolithic Period. The earliest agriculturalists of the Fertile Crescent accidentally triggered fermentation with the addition of honey to fruits juices, as attested to in the archaeological record.