Budding yeast Saccharomyces cerevisiae has been a wonderful model system in the research of membrane traffic. It is needless to say that identification of SEC genes by Randy Schekman’s group has played a pioneering role in this field. There has also been an advantage in yeast for imaging research. Namely, yeast Golgi cisternae do not stack, so that cisternal maturation has been clearly demonstrated by light microscopy (Matsuura-Tokita et al., Nature 441:1007, 2006).

New discoveries follow. We have found that the cis-Golgi cisternae show repeated approach to the ER exit sites (assembly sites for COPII vesicles) to capture cargo, not in the generally believed way of budding and release of free vesicles. We call this “hug-and-kiss” action (Kurokawa et al., Nat. Commun. 5:3653, 2014).

We will investigate how proteins are sorted at the entry and the exit of the Golgi apparatus and how cargo and resident proteins are distinguished during inter-cisternal transport by the new-generation SCLIM, SCLIM2.
We have also shown that different types of cargo are sorted from each other during the exit from the ER and are trying to elucidate the underlying mechanisms. (KAKENHI: Grant-in-Aid for Scientific Research on Innovative Areas “Organelle Zone”)