Figure 1

Global view of the protein secretory pathway in filamentous fungi showing the location of the COPII complex in coated vesicles budding from the ER and merging to the Golgi complex where the CkiA (casein kinase) is involved in the vesicle coat removal and fusion of vesicles with the Golgi. The PMR1 Ca²⁺/Mn²⁺ transporter ATPase is located in the Golgi membranes. Finally the amino acid permeases located in the cytoplasmic membrane are shown. The targeting of these amino acid permeases is governed by CkiA. The CPPs produce an overall stimulation of the forward traffic of secretory proteins by altering the Ca²⁺ concentration gradients in the organelles (solid arrow in the botton, see text for details).