Plasma membrane compartmentalization in yeast by messenger RNA transport and a septin diffusion barrier

Asymmetric Localization of proteins plays a key role in many cellular proce sses, including cell polarity and cell fate determination. Using DNA microa rray analysis, we identified a plasma membrane protein-encoding mRNA (IST2) that is transported to the bud tip by an actomyosin-based process. mRNA lo calization created a higher concentration of IST2 protein in the bud compar ed with that of the mother cell, and this asymmetry was maintained by a sep tin-mediated membrane diffusion barrier at the mother-bud neck. These resul ts indicate thar yeast creates distinct plasma membrane compartments, as ha s been described in neurons and epithelial cells.