ppt课件-国外大学细胞生物学ppt课件-英文10.bioy.ppt

W2011 D103 Cell Biology - lecture 10 ? Suetterlin and MacGregor - all rights reserved. * General concepts of protein sorting Protein import into cytosolic organelles Mitochondria Nucleus Lecture 10: Protein sorting in the cytosol W2011 D103 Cell Biology - lecture 10 ? Suetterlin and MacGregor - all rights reserved. * Unique protein composition Unique lipid composition Unique localization within the cell How is organelle-specific protein composition achieved? specialized function What determines the identity of an organelle? W2011 D103 Cell Biology - lecture 10 ? Suetterlin and MacGregor - all rights reserved. * Protein sorting in the cytosol ? All cellular proteins are synthesized on the same pool of cytosolic ribosomes. ? Protein transport out of the cytosol requires sorting information W2011 D103 Cell Biology - lecture 10 ? Suetterlin and MacGregor - all rights reserved. * 1. SORTING SIGNAL ? necessary to direct the protein to the new location ? sufficient to direct any (neutral) protein to that location 2. TRANSLOCATION-COMPETENT STATE 3. RECEPTOR ? recognizes the sorting signal ? bring the protein to the translocation machinery 4. TRANSLOCATION MACHINERY ? moves protein to the new location 5. DRIVING FORCE ? energy 6. CARGO RELEASE 7. FOLDING Aspects to consider during protein sorting W2011 D103 Cell Biology - lecture 10 ? Suetterlin and MacGregor - all rights reserved. * necessary: it should direct a protein into a new, membrane-bound compartment ? Protein should be protected from protease sufficient: it should direct a neutral protein (without sorting information) to the new environment It should specifically interact with a binding partner/receptor ? It can be removed from the protein upon arrival in target location What is expected of a sorting signal? W2011 D103 Cell Biology - lecture 10 ? Suetterlin and MacGregor - all rights reserved. * Protein transport pathways The protein sorting destinations of mitochondria W2011