蛋白質分泌系統在細菌的生理功能扮演非常重要的角色。許多病原細菌會藉由分泌特定的蛋白質或核酸等大分子，進而幫助細菌適應複雜的生長環境，影響其致病力或於宿主中生存的能力。因此，研究細菌蛋白質分泌系統的分泌機制及其生理功能是非常重要的研究課題。本課程將介紹蛋白質如何在細菌細胞內運輸、穿過細胞膜、分泌到細胞外或進入宿主細胞內的分子機制及其分泌蛋白質之功能。將著重在與病原細菌致病能力有關之蛋白質分泌系統，並針對新近重要文獻進行討論。 secretion systems play central roles in the export or import of macromolecules in both prokaryotic and eukaryotic cells. This course will introduce how proteins are translocated across membranes and secreted outside of bacterial cells or even transported into the hose cells. The biological functions of secretion systems will be also discussed with focus on pathogenic bacteria. The course will cover 1) lectures and 2) paper discussion.