国外大学细胞生物学课件 英文课件11.ppt

1 Lecture 11: Protein sorting II Protein import into the ER Processes in the ER W2011 D103 Cell Biology - lecture 11 ? Suetterlin and MacGregor - all rights reserved. 2 The smooth ER ? Production of lipoprotein particle ( hepatocytes ) ? Detoxification from lipid soluble drugs and other pounds ? Vesicle formation ? Calcium storage ( sarcoplasmic reticulum in smooth and striated muscle fibers) ? Synthesis of cholesterol and cholesterol-derived hormones ? Synthesis of phospholipids smooth ER W2011 D103 Cell Biology - lecture 11 ? Suetterlin and MacGregor - all rights reserved. The smooth ER is a site of lipid synthesis 3 W2011 D103 Cell Biology - lecture 11 ? Suetterlin and MacGregor - all rights reserved. The rough ER 4 rough ER Major site of protein import into the ER Entry point of the secretory pathway Site where the topology of proteins is determined W2011 D103 Cell Biology - lecture 11 ? Suetterlin and MacGregor - all rights reserved. 5 The ER signal sequence and SRP ? Signal hypothesis: Nobel prize for Gunther Blobel in 1999 W2011 D103 Cell Biology - lecture 11 ? Suetterlin and MacGregor - all rights reserved. SRP binds its substrate via a hydrophobic domain. 6 ? Multimeric plex that creates an aqueous channel in the ER membrane The translocon W2011 D103 Cell Biology - lecture 11 ? Suetterlin and MacGregor - all rights reserved. 7 W2011 D103 Cell Biology - lecture 11 ? Suetterlin and MacGregor - all rights reserved. Mechanism of protein translocation into the ER 8 W2011 D103 Cell Biology - lecture 11 ? Suetterlin and MacGregor - all rights reserved. Cytosolic ribosomes synthesize proteins that are targeted to the ER. 9 W2011 D103 Cell Biology - lecture 11 ? Suetterlin and MacGregor - all rights reserved. 10 co-translational Post-translational W2010 D103 Cell Biology - lecture 11 ? Suetterlin and MacGregor - all rights reserved. Two mechanisms of protein translocation post-translational (Yeast) Involves ad