Newly made secretory proteins are localized to the lumen of the rough ER. Proteins destined to be secreted move through the secretory pathway in the following order: rough ER → ER-to-Golgi transport vesicles → Golgi cisternae → secretory or transport vesicles → cell surface (exocytosis) (see Figure 17-13).Click to see full answer. Similarly one may ask, what is the path of a protein through the Endomembrane system? Path of a Secretory Protein Through the Endomembrane System The proteins move through the endomembrane system and are dispatched from the trans face of the Golgi apparatus in transport vesicles that move through the cytoplasm and then fuse with the plasma membrane releasing the protein to the outside of the cell.Additionally, where does protein and lipid synthesis occur? Lipids and proteins are synthesized on the endoplasmic reticulum. Ribosomes are the site for protein synthesis. Secondly, what is the process of protein secretion? Protein Secretion. Protein secretion is a multistep process that involves vesicle biogenesis, cargo loading, concentration and processing, vesicle transport and targeting, vesicle docking and Ca2+-dependent vesicular fusion with the plasma membrane.What produces proteins destined for secretion from the cell?Proteins destined for secretion or incorporation into the ER, Golgi apparatus, lysosomes, or plasma membrane are initially targeted to the ER. In mammalian cells, most proteins are transferred into the ER while they are being translated on membrane-bound ribosomes (Figure 9.3).