Translating Co-Translational Translocation

Abstract

Understanding the process of proteins targeting to specific locations within a cell is a fundamental part of cell biology. Synthesis of proteins by co-translational translocation, which also determines the resulting protein topology, is a complex process that is often difficult for students to understand. Our goal was to create an engaging lesson to stimulate critical and experimental thinking and help students more effectively learn about co-translational translocation. In the first part of the lesson, students complete a strip sequence activity to order the basic events of co-translational translocation. This activity stimulates peer and class discussion that helps students engage with the material and generate and answer questions. In the second part of the lesson, students complete a four-part guided worksheet that introduces two versions of the protease protection assay with a secretory protein and uses the protease protection assay to evaluate the topology of transmembrane proteins with different types of ER signal sequences. Student responses to in-class clicker questions and exam questions assess student learning. Student survey results indicate the activity was engaging, not confusing, and was helpful for most students.