BIOB10H3 Lecture Notes - Lecture 6: Asparagine, Selectin, Protein Disulfide-Isomerase
Document Summary
Endomembrane system- endoplasmic reticulum, golgi complex, lysosomes and endosomes, vacuoles. Each have specific, unique functions ie. each have unique proteins. Proteins contain sorting signals that target them to particular subcellular destinations. Ecm matrix proteins (fibroblasts/osteoblasts) eg. collagen of connective tissue - Digestive enzymes of the gut (pancreatic, liver & intestinal cells) Adhesion molecules - to ecm or to other cells, glycocalyx, receptors and ion channels. Palade et al: - looked at route taken by secreted proteins in pancreatic acinar cells. Pulse-chase with radioactive amino acids, followed by autoradiography to detect radioactive proteins. Gfp-fusion proteins green fluorescent protein follow proteins in live cells in real time ts mutant cargo protein allows accumulation in donor compartment lower temperature allows transport to proceed. Proteins contain a signal sequence (~ 20 amino acids including a stretch of > 8 hydrophobic residues) at their amino terminus that targets them to the er. Attached to rer via signal sequences on polypeptide chains during their synthesis.