The hepatocellular secretory pathway

This chapter focuses on the molecular mechanisms by which nascent proteins and larger cargos are sequestered, packaged into vesicle carriers, and targeted to specific hepatocellular destinations during the secretory process. The secretory pathway begins with synthesis of proteins at the endoplasmic reticulum. The chapter describes some of the molecular components required to direct nascent proteins and more complex lipoprotein particles from the endoplasmic reticulum (ER) to the Golgi apparatus and then to their final destination. Coat protomer I coated vesicles are required for intra-Golgi trafficking and for recycling from the Golgi apparatus back to the ER. The first cis-Golgi element and the trans-Golgi network are tubular membrane meshworks at the entry and exit sides of the Golgi apparatus, respectively. Transport in the anterograde direction from the ER to the Golgi apparatus is mediated by coat protomer II coated vesicles.