MBB 231 Lecture Notes - Lecture 13: Lysosomal Storage Disease, Endosome, Mannose
Document Summary
Mbb 231: be clear on what makes up the endomembrane system, understand (in detail) the role of a kdel sequence (lys-asp-glu-leu) Most soluble resident er proteins carry kdel seq in their c terminus. The golgi complex employs a receptor protein that binds to the kdel sequence and delivers the targeted protein back to the er. Serves as recogniion device that allows the golgi complex to selecively package such proteins into newly forming lysosomes. Targeing of soluble lysosomal enzymes to endosomes and lysosomes by a mannose- In the er, soluble lysosomal enzymes undergo n-glycosylaion followed by removal of glucose and mannose units: within the golgi complex, mannose residues on the lysosomal enzymes are phosphorylated by two enzymes. The irst one adds n-acetylglucosamine-1-phosphate to carbon atom 6 of mannose. The late endosome either matures to form a lysosome or transfers its contents to an acive lysosome. M6p residues are added in the cis golgi.