文档介绍：Lecture 14: Exocytosis - Endocytosis 1 W11 D103 Cell Biology - lecture 13 ? Suetterlin and MacGregor - all rights reserved. Protein secretion W11 D103 Cell Biology - lecture 13 ? Suetterlin and MacGregor - all rights reserved. 2 Transport across the Golgi stack Transport from Golgi to the cell surface Transport to the lysosome How are proteins transported across the Golgi? 50 to 70 nm 400 nm 300 nm 3 W11 D103 Cell Biology - lecture 13 ? Suetterlin and MacGregor - all rights reserved. (= Lipoprotein particles: 85-92 % triglycerides 6-12 % phospholipids 1-3 % chlolesterol 1-2 % protein) 4 Models for protein transport across the Golgi cis-Golgi trans-Golgi W11 D103 Cell Biology - lecture 13 ? Suetterlin and MacGregor - all rights reserved. 5 N-glycans processing during Golgi transport Fig 14-14 Function for N-glycosylation : ER : quality control cis-Golgi : required for the generation of a lysosomal sorting signal (M6P) Plasma membrane : protection, interaction with neighboring cells W11 D103 Cell Biology - lecture 13 ? Suetterlin and MacGregor - all rights reserved. 6 The distinct destinations of a protein in the TGN TGN Stay in the Golgi not well understood constitutive transport to cell surface vesicle coat and mechanism of cargo Recruitment are not well understood) regulated transport to cell surface transport to endosome ? lysosome W11 D103 Cell Biology - lecture 13 ? Suetterlin and MacGregor - all rights reserved. The lysosome 7 ? Diverse in shape and size ? fulfill variety of digestive functions: - breakdown of intra/extracellular debris - destruction of phagocytosed anisms - nutrient production for the cell ? very low pH due to ATP-driven proton pump How do lysosomal proteins reach the lysosome? W11 D103 Cell Biology - lecture 13 ? Suetterlin and MacGregor - all rights reserved. 8 Protein transport to the endosome /lysosome W11 D103 Cell Biology - lecture 13 ? Suetterlin and MacGregor - all rights reserved. 1. The coat