Over-expression of functional Saccharomyces cerevisiae GUP1, induces proliferation of intracellular membranes containing ER and Golgi resident proteins

► High-level expression of GUP1 gene in S. cerevisiae resulted in the formation of proliferated structures. ► The Gup1 protein-induced proliferations showed that they are a hybrid compartment, including resident ER, Golgi and itinerant proteins. ► The Gup1p MBOAT activity was needed for the membranaceous arrangements formation.