Trans-species complementation analysis to study function conservation of plant Endosomal Sorting Complex Required for Transport (ESCRT) proteins.

ESCRT (Endosomal Sorting Complex Required for Transport) proteins are required for the sorting of biosynthetic and endocytic proteins at multivesicular bodies (MVBs). Here, I describe an assay to evaluate conservation of endosomal sorting functions of plant ESCRT proteins by trans-species complementation analysis. The assay is based on the imaging of a fluorescent biosynthetic MVB cargo, the carboxypeptidase S (CPS) fused to the green fluorescent protein GFP, in yeast ESCRT mutants expressing putative plant orthologues of the missing yeast ESCRT components.