Lecture 12: Protein Transport in Cells PDF

11.Gated Membrane Transport and Transmembrane Transport Part 1 Gated transport (nucleus-cytosol) Transport to the endomembrane system –Translocation of proteins into the mitochondrion or chloroplast –Translocation of proteins into the peroxisome –Translocation of proteins into the ER Which organelle...

11.Gated Membrane Transport and Transmembrane Transport Part 1 Gated transport (nucleus-cytosol) Transport to the endomembrane system –Translocation of proteins into the mitochondrion or chloroplast –Translocation of proteins into the peroxisome –Translocation of proteins into the ER Which organelles are part of the endomembrane system? can’t merge with vesicles vesicles that have a collection of materials brought in from outside the cell digest and break down materials How did the endomembrane system evolve? Loading… 3 Types of Transmembrane Transport Gated membrane Transport – Nuclear transport – Folded proteins between nucleus and cytosol Transmembrane Transport – Into mitochondria and peroxisome – Into endomembrane system – Unfolded proteins from cytosol to organelle Vesicular Transport – Endocytosis and Exocytosis – Folded proteins carry vesicles to organelles of the endomembrane system Proteins have “addresses” Sequence of amino acids in the protein 15-60aa signal sequences Cleaved by signal peptidases Sequence specifies destination RecognizedLoading… by sorting receptors Signal sequences v. signal patches I located a N-terminus -terminus at the Gated Transport: Nuclear Transport ↳ ↳ continuous wil The e gee helps Inner and outer membrane continuous with ER Inner membrane: binding sites for chromatin, Nuclear lamina (support) Bidirectional traffic with nucleus uses pores Sisterections Nucleoporins are the proteins that make the nuclear pore. Nuclear Transport Transmembrane Transport into Mitochondria Transmembrane Transport into Peroxisomes Loading… Putting Proteins into FR , are the ER & ribosomes on the membrane the are Co-translational v. Post-translational proteins translated and enter into the ER at the same time for see peroxisomes - Mitochondria and encoplasts de > - Lastthesamepe translated time (after the protein Is completed the are and proteins translated then carried to their destinationa But into the organellineie supposed De to 11.Gated Membrane Transport and Transmembrane Transport Part 1 Gated transport (nucleus-cytosol) Transport to the endomembrane system –Translocation of proteins into the mitochondrion or chloroplast –Translocation of proteins into the peroxisome –Translocation of proteins into the ER Which organelles are part of the endomembrane system? How did they evolve? Complete the table below Type of Transport Gated Protein folded or unfolded Loading… Folded Transmembrane Vesicular Protein comes from Unfolded Folded Cytosol Cytosol Endomembrane Protein moves to Nucleus Mitochondria Perixosmes Chloroplast ER Endomembrane How long are signal sequences? 15-60ca How does the signal direct the protein? Where are signal sequences located? Loading… Signal sequences are often cleaved by a signal peptidase. Do you think signal patch is also cleaved? No What are the 3 types of protein transport? Gated transport Transmembrane transport via protein Translocators Vesicular transport Label the parts of the nucleus Outer membrane Inner membrane ER membrane ER lumen Nuclear lamina Perinuclear envelope Nuclear pores T orO F Proteins entering the nucleus enter unfolded. T or F Nuclear proteins require a specific signal · sequence in order to bind an import receptor. T or F ATP is required for movement of proteins O through the nuclear pore. T orO F The nuclear protein leaves the import receptor because of the pH difference between the nucleus and the cytoplasm. T or F O The import receptors are recycled to the cytosol. Draw or write the steps of nuclear import. Draw or write the steps of nuclear import. Ran-GAP RAN-GEF Make a Venn diagram comparing gated transport and transmembrane transport into mitochondria or chloroplasts Loading… What are the steps of protein translocation into the mitochondrion? Transmembrane Transport into Mitochondria What is the difference between cotranslational and post-translational transport? Zellweger Syndrome Zellweger syndrome is one of a group of four related diseases called peroxisome biogenesis disorders (PBD). The diseases are caused by defects in any one of 13 genes, termed PEX genes, required for the normal formation and function of peroxisomes.