Biology 2382B Lecture Notes - Lecture 4: Cisterna, Collagen, Translocon
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Newly made peptides must be directed to the correct destination - must be localized correctly. Sorting = decide whether secretory pathway or not direct proteins only in regards to the secretory pathway (er, golgi, lysosomes) So: if you"re going straight to the organelle in the first place = targeting; if you"re takin" the scenic route/peacin" out of the cell - sorting. Targeting = direct proteins to the right destinations (organelles) during or after synthesis = much more specific than sorting. Always happens after sorting, regardless of the outcome of sorting. Proteins need to be tagged for the right destinations/organelles. Remember: there is not empty space in a cell - if something is moving around, something else is taking it - targeting means you"re moving on" something. Secretory = other proteins are synthesized by ribosomes attached to the rough er. Then they have to be targeted, post-sorting. Non-secretory = many proteins are synthesized just by cytosolic ribosomes: