2 - September 10, 2008 Lecture 2 Intracellular processing...

Info iconThis preview shows pages 1–10. Sign up to view the full content.

View Full Document Right Arrow Icon
1 Intracellular processing and transport of ECM molecules Molecular Organization of collagens Collagen Classification Fibrillar collagens: structure and assembly of type I collagen (prototype) Intracellular Processing September 10, 2008 Lecture 2
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
2 Overview of Intracellular Protein Traffic nucleus Secretory Pathway for ECM molecules mRNA Translation arrest Endoplasmic reticulum Golgi NH 2 COOH Secretory vesicles Figure 12-6. Molecular Biology of the Cell, 4 th edition Plasma membrane
Background image of page 2
3 http://www.molecularexpressions.com/cells/animals/images/animalcellsfigure1.jpg Anatomy of a cell How does a cell decide which proteins are destined to be translated in the cytoplasm or in the endoplasmic reticulum?
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
4 AUG (A) N 3’ 5’ NH 2 S i g n al p e t d Synthesis of a protein destined for the ER 1) Translation begins in the cytosol 2) When ~ 70 amino acids have been polymerized, the signal peptide is no longer masked by the ribosome 3) A signal recognition particle can now bind to the signal peptide
Background image of page 4
5 Amino acid sequences of signal peptides of several eukaryotic secretory and membrane proteins Protein Amino acid sequence Preproalbumin Met- Lys - Trp-Val-Thr-Phe-Leu-leu-leu-leu-Phe-Ile -Ser-Gly-Ser- Ala-Phe-Ser Arg. ..... Pre-IgG light Met-Asp-Met- Arg - Ala-Pro-Ala-Gln-Ile-Phe-GLy-Phe-Leu-Leu-Leu- chain Leu--Phe-Pro-Gly-Thr -Arg-Cys Asp. ..... Prelysozyme Met- Arg -Ser- Leu-Leu-Ile-Leu-VaL-Leu-Cys-Phe-Leu-Pro-Leu-Ala- Ala-Leu-Gly Lys. ..... Preprocollagen Met-Leu-Ser-Phe-Val-Asp-thr- Arg - The-Leu-Leu-Leu-Leu-Ala-Val- type I Thr-Cys-Ala-Tyr-Leu- Gln Ser-Gly-Ser-Val. ..... SPARC/ Met- Arg - Ala-Trp-Ile-Phe-Phe-leu-Leu-Cys-Leu-Ala-Gly- Arg-Ala- Osteonectin Leu-Ala Ala-Pro-Gln. ..... Signal peptides motifs: a continuous stretch of 6-30 hydrophobic residues flanked by one or more basic residues to the N-terminal side Signal peptidase cleavage sites
Background image of page 5

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
6 How ER signal peptide sequences and SRP direct ribosomes to the ER membrane The signal peptide is exposed when ~70 amino acids have been synthesized Figure 12-42 part 2 of 2. Molecular Biology of the Cell, 4 th edition
Background image of page 6
7 How ER signal peptide sequences and SRP direct ribosomes to the ER membrane Protein translocator “Sec61 complex” Figure 12-42 part 2 of 2. Molecular Biology of the Cell, 4 th edition 2GTP -- Æ 2GDP + 2P i One GTP each for SRP and translocator Co-translation translocation”
Background image of page 7

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
8 Mammalian signal-recognition particle: six proteins and one RNA Figure 12-41. Molecular Biology of the Cell, 4 th edition Crystal structure of the signal-sequence-binding domain: contains a large, exposed binding pocket that is lined with a large number of hydrophobic methionine residues The Met residues (which form a flexible, unbranched chain) bind to the hydrophobic domain of signal peptides P54
Background image of page 8
Signal peptidase Signal peptide How a single-pass transmembrane protein with a cleaved ER signal is integrated into the ER membrane Figure 12-46. Molecular Biology of the Cell, 4 th edition Signal peptide has two functions: 1)
Background image of page 9

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 10
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 09/29/2009 for the course CSB csb327 taught by Professor Ringuitte during the Fall '08 term at University of Toronto- Toronto.

Page1 / 36

2 - September 10, 2008 Lecture 2 Intracellular processing...

This preview shows document pages 1 - 10. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online