2022-10-21T04:50:19+03:00[Europe/Moscow] en true <p>How are proteins sorted to the ER?</p>, <p>What are the 2 major functions of the ER?</p>, <p>How do proteins know they should go to the ER?</p>, <p>What are the steps in how proteins are sorted into the Endoplasmic Reticulum?</p>, <p>What is SRP, what does it do?</p>, <p>What is the ER signal sequence also called?</p>, <p>How does the protein actually get made from the ribosomes straight into the cell?</p>, <p>What are the three types of single-pass transmembrane proteins?</p>, <p>How does the stop transfer intermembrane protein get imbedded?</p>, <p>How do the other two intermembrane proteins get imbedded?</p>, <p>How does multipass transmembrane protein get embedded if N terminus is more positive?</p>, <p>How does multipass transmembrane protein get embedded if C terminus is more positive?</p>, <p>What are the 3 membrane protein types?</p>, <p>How to anchor protein onto GPI anchor?</p> flashcards

Bio230 week 6

Protein sorting

Customize
collection saved
Share
Long Term Learning Spaced Repetition
Add to Long Term Learning Desk
Fast learning Repeat this set of flashcards
Preview Test Spell
Play
Match
Review

  • How are proteins sorted to the ER?

    Transmembrane transport then further sorted by vesicular transport to other compartments or to cell surface.

  • What are the 2 major functions of the ER?

    Synthesis and modifications of proteins (rough)

    Synthesis of lipids (smooth)

  • How do proteins know they should go to the ER?

    They have an ER signal sequence. These proteins include soluble proteins, transmembrane proteins, proteins destined for Golgi, secretion and lysosomes

  • What are the steps in how proteins are sorted into the Endoplasmic Reticulum?

    1. mRNA + Ribosomes2. Translation starts but there's an ER signal sequence (emerges first at N-terminus hydrophobic)3. Ribosomes directed to ER membrane (SRP)4.Co-Translational translocation

    1. mRNA + Ribosomes

    2. Translation starts but there's an ER signal sequence (emerges first at N-terminus hydrophobic)

    3. Ribosomes directed to ER membrane (SRP)

    4.Co-Translational translocation

  • What is SRP, what does it do?

    Signal Recognition Particle and SRP receptor have GTPase domains that bind GTP. SRP + Ribosome=Low affinitySRP + ribosome + ER signal sequence = high affinity and binds to SRP receptorBinding of SRP causes translation to pause

    Signal Recognition Particle and SRP receptor have GTPase domains that bind GTP.

    SRP + Ribosome=Low affinity

    SRP + ribosome + ER signal sequence = high affinity and binds to SRP receptor

    Binding of SRP causes translation to pause

  • What is the ER signal sequence also called?

    N-Terminal start-transfer sequence

  • How does the protein actually get made from the ribosomes straight into the cell?

    ER signal sequence is bound to the translocator

    Protein is fed through translocator

    signal peptidase cleaves signal

    Protein is in ER

  • D

  • What are the three types of single-pass transmembrane proteins?

    1.Stop Transfer sequence2/3.Internal start transfer sequence

    1.Stop Transfer sequence

    2/3.Internal start transfer sequence

  • How does the stop transfer intermembrane protein get imbedded?

    N terminal signal sequence goes through translocator like normal. Translocator reaches a stop transfer sequence. Rest of protein gets made in cytosol. Signal peptidase cleaves signal sequence. COOH in cytosol

  • How do the other two intermembrane proteins get imbedded?

    Ribosome makes it, there's an internal start transfer sequence. the more positive side of each end of the sequence ends up in the cytosol

    Ribosome makes it, there's an internal start transfer sequence. the more positive side of each end of the sequence ends up in the cytosol

  • How does multipass transmembrane protein get embedded if N terminus is more positive?

    Translocator finds more positive side that one goes to cytosol. Translocator reaches stop-transfer sequence. You get a multipass. Both N-terminus and C-terminus in cytosol.

    Translocator finds more positive side that one goes to cytosol. Translocator reaches stop-transfer sequence. You get a multipass. Both N-terminus and C-terminus in cytosol.

  • How does multipass transmembrane protein get embedded if C terminus is more positive?

  • C

  • What are the 3 membrane protein types?

    IntegralLipid anchoredPeripheral

    Integral

    Lipid anchored

    Peripheral

  • How to anchor protein onto GPI anchor?

    Target protein has C terminal in cytosol. Transamidase comes in and takes pre formed GPI anchor, mediate a cut at ER lumen side of protein and attach it to GPI anchor. GPI anchored protein ends up on ER lumen side and can go to cell exterior surface

    Target protein has C terminal in cytosol. Transamidase comes in and takes pre formed GPI anchor, mediate a cut at ER lumen side of protein and attach it to GPI anchor. GPI anchored protein ends up on ER lumen side and can go to cell exterior surface