BIOL 200 Lecture Notes - Lecture 23: Cytosol, Cell Membrane, Autoimmune Disease
Document Summary
All (cid:862)cargo(cid:863) proteins passing through golgi are sorted in the tgn. Lysosomal pathway: lysosomal proteins have a core sugar transferred to them from dolichol. This is trimmed and processed so that it consists primarily of mannose sugars: an enzyme transfers a phosphate to the mannose sugars so that they become mannose- Processing of proteins via proteolytic cleavage: many proteins require further processing as they move away from the trans golgi network (e. g. in secretory vesicles, proteolytic cleavage of pro-proteins produces small, active proteins (e. g. digestive enzymes) Active enzymes in the golgi could be very bad for the surrounding environment. Mannose-6-phosphate (m6p) receptor dissociates from its cargo, a m6p-tagged protein in the late endosome because of the acidic environment of the late endosome. Note: the ph gradient decreases (from neutral to weakly acidic to acidic) as we go from the er to the trans golgi network and out into the extracellular space from the cytosol through the plasma membrane.