UC San Diego

The Golgi is surrounded by a ribosome-excluding matrix. Recently, we reported that the cis-Golgi-localized golgin GM130 can phase-separate to form dynamic, liquid-like condensates in vitro and in vivo. Here, we show that the overexpression of each of the remaining cis (golgin160, GMAP210)- and trans (golgin97, golgin245, GCC88, GCC185)-golgins results in novel protein condensates. Focused ion beam scanning electron microscopy (FIB-SEM) images of GM130 condensates reveal a complex internal organization with branching aqueous channels. Pairs of golgins overexpressed in the same cell form distinct juxtaposed condensates. These findings support the hypothesis that, in addition to their established roles as vesicle tethers, phase separation may be a common feature of the golgin family that contributes to Golgi organization.