ABSTRACT
This chapter examines the secretion and processing of mammalian interferon (IFN) gene products in the lower eukaryote yeast. Interferon activity remaining inside the cell after cell wall removal is defined as interferon activity that is not secreted. Interferon activity found in the medium plus the activity released from the cells after cell wall removal by the enzyme zymolyase together represent the total secreted material. One possible explanation for finding IFN in the medium was that the pre-sequence of interferon somehow makes the cells more susceptible to lysis during growth. Cell extracts also contain the IFN from the periplasmic space since the cell wall was not removed prior to extract preparation. The yeast pathway appears to start with translation of the pre-protein at the endoplasmic reticulum where the pre-sequence is removed after passage through the membrane, and then transported to the Golgi where vesicle intermediates are formed.
