Working scheme building CUPS-modified TGN for unconventional secretion. During growth, cells predominantly depend on the conventional ER–Golgi pathway of protein secretion. When cells are cultured in starvation medium, there is a sharp reduction in the use of conventional secretory pathway and the cells switch to a new or an unconventional mode to release essential proteins to the cell’s exterior. A cis-Golgi membrane produces small fragments, which do not contain glycosylation enzymes, in a COPI-independent manner to synthesize CUPS (magenta). The early TGN produces small membranes to generate a compartment that we have called the modified TGN (green). Our data show that tubules emanating from the modified TGN are collared by CUPS, which is followed by severing of the tubule. We suggest that these contacts, over a period, lead to the consumption of the modified TGN to produce smaller elements (vesicles + tubules). These smaller elements are likely used for delivering essential proteins to other compartments of the cell and releasing proteins such as SOD1 and Acb1 to the cell’s exterior. This mode of TGN consumption is common to both the conventional and unconventional protein secretion processes. Upon shifting cells to growing conditions, components of the CUPS are delivered by COPI vesicles to the ER, which then traffic the respective components to the Golgi, thereby restoring the Golgi to restart the conventional mode of protein secretion.