Biological Science (7th Edition)
7th Edition
ISBN: 9780134678320
Author: Scott Freeman, Kim Quillin, Lizabeth Allison, Michael Black, Greg Podgorski, Emily Taylor, Jeff Carmichael
Publisher: PEARSON
expand_more
expand_more
format_list_bulleted
Concept explainers
Videos
Textbook Question
Chapter 7, Problem 7TYU
Most of the proteins that enter the nucleus possess a nuclear localization signal (NLS), even if they are small enough to pass through the nuclear pore complex unhindered. Why would a small protein have an NLS, when it naturally diffuses across the nuclear pore complex without one?
Expert Solution & Answer
Want to see the full answer?
Check out a sample textbook solution
Students have asked these similar questions
Rather surprisingly, some cellular components that we know best from our study of nuclear protein traffic also appear to be involved in the process of spindle assembly. These include Ran GEF (which, as you may recall, is bound to chromatin – an association that apparently continues even when the nuclear envelope breaks down at the onset of mitosis) and importin-β. Now think back to the process of nuclear protein import. To which form of Ran (Ran-GDP or Ran-GTP) does importin-β bind and what is the significance of that interaction with respect to the efficiency of delivery of import “cargo” to the nucleus? To which form of Ran (Ran-GDP or Ran-GTP) do exportins bind and what is the significance of that interaction with respect to the efficiency of delivery of export “cargo” to the cytoplasm?
As we learned when studying protein trafficking, proteins need a nuclear localization signal in order to move from the cytosol into the nucleus via the nuclear pore complex. Protein A contains a typical nuclear localization signal but surprisingly is usually found in the cytosol. When the cell is exposed to a certain hormone, protein A moves from the cytosol into the nucleus, where it turns on genes involved in cell division.When you purify protein A from cells that have not been treated with the hormone, you find that protein B is always complexed with it. To determine the function of protein B, you engineer cells lacking the gene for protein B. You compare normal and gene B deletion cells by separating and isolating the proteins found in the cytoplasm and those found in the nucleus. You then run these proteins on a protein electrophoresis gel to separate them by size. You identify the presence of protein A and protein B by looking for their characteristic bands on the gel (which is…
What is the structure of the translocation channel that allows transfer of proteins across the membrane bilayer? In particular, is the channel so narrow that proteins can pass through only in an unfolded state, or will it accommodate folded protein domains?
Chapter 7 Solutions
Biological Science (7th Edition)
Ch. 7 - What are three attributes of mitochondria and...Ch. 7 - PROCESS OF SCIENCE Which of the following results...Ch. 7 - Molecular zip codes direct molecules to particular...Ch. 7 - How does the hydrolysis of ATP result in the...Ch. 7 - Prob. 5TYUCh. 7 - 7. Most of the proteins that enter the nucleus...Ch. 7 - Prob. 11PIATCh. 7 - 12. MODEL The distribution of melanosomes in cells...Ch. 7 - Prob. 15PIATCh. 7 - Prob. 16PIAT
Knowledge Booster
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, biology and related others by exploring similar questions and additional content below.Similar questions
- The following image is based on real results from an influential experiment in cell biology. This experiment studied the role of the proteins Ran and importin in nuclear protein transport. The experiment used flourescently-labeled proteins containing a nuclear localization sequence (the "substrate"). Ran, importin, and GTP were either present or absent, as indicated in the figure. Cells were exposed to these different conditions and then analyzed by fluorescence microscopy. Circles are the cells' nuclei. Very light circles are the nuclei without the substrate attached. Study the figure below and then answer the questions that follow. 1. What actions does Ran perform by itself? 2. What actions does importin perform by itself? 3. How do Ran and importin act together in the nuclear import of protein? 4. Why is GTP required?arrow_forwardwhy is nuclei stained purple but the cytoplasmic components are pink in eosin?arrow_forwardYou are investigating a lysosomal storage disease and you discover that newly synthesized lysosome hydrolases (proteins that should be sent to the lysosome) are secreted from the cells rather than being delivered to the lysosomes (where they should normally be located). What is the most likely explanation for this finding? (Hint: what might be different about the proteins that would cause them to not end up in the correct location?)arrow_forward
- A peripheral protein, which is not integral to the cell membrane, is also called: a multi-pass transmembrane protein (like band 3.0 protein) a single-pass transmembrane protein (like glycophorin A) a monolayer-associated protein (like the COX-1 protein) a protein-attached protein (like cytochrome c) a lipid-linked protein (like the Ras protein)arrow_forwardThe nucleus is the largest of the eukaryotic organelles and contains the genome of the organism. a) describe the proteins and process of nuclear import and export. b) describe, in general terms, an experiment that could be conducted to show that there are specific signals for nuclear import or export.arrow_forwardThe fragments of huntingtin protein also form aggregates with a nuclear transport protein known as Ran-GAP. How does Ran-GAP aggregating with huntingtin protein fragments disrupt nuclear protein transport?arrow_forward
- Which describes an enzymatic activity/biochemical function of importin-beta? facilitate release of nuclear proteins after transport through the nuclear pore complex interact with/bind to nuclear localization sequences INLSS) interact with/bind to importin-alpha hydrolyze GTP to GDP + Piarrow_forwardThe figure above shows the organization of a protein that will eventually reside in the plasma membrane. The boxes labeled 1 and 2 represent membrane-spanning sequences and the arrow represents a site of action of signal peptidase. Which of the following statements must be TRUE about this protein? O a) Most of this protein will project from the cytosolic side of the membrane. O b) The mature version of this protein will span the membrane twice. c) This is a multi-pass membrane protein. O d) The mature version of this protein will span the membrane once.arrow_forwardIf 17 Beta estradiol can diffuse through cell membranes, explain why all cell types are not sensitive to the presence of 17 beta estradiol?arrow_forward
- Many of the cell’s hydrolytic enzymes are located in the lysosome, where the pH is ∼5. What would you expect to be the optimum pH for these enzymes, and why would this protect the rest of the cell from the destructive power of these enzymes upon the accidental rupture of a lysosome?arrow_forwardWhat would most likely occur to nuclear-cytoplasmic shuttling if the intrinsic GTPase activity of RAN was slowed down by 50%? Group of answer choices RAN would not bind exportin and proteins would accumulate in the nucleus All of the answers are likely None of the answers are likely Importin beta would not release from RAN in the cytoplasm and nuclear import would slow down RAN would not bind to importin beta and protein cargo in the nucleus would not releasearrow_forwardExplain the mechanism by which the fungal toxin brefeldin A affects retrieval of KDEL-tagged proteins from the cis-Golgi network back to the endoplasmic reticulum.arrow_forward
arrow_back_ios
SEE MORE QUESTIONS
arrow_forward_ios
Recommended textbooks for you
Human Anatomy & Physiology (11th Edition)BiologyISBN:9780134580999Author:Elaine N. Marieb, Katja N. HoehnPublisher:PEARSON
Biology 2eBiologyISBN:9781947172517Author:Matthew Douglas, Jung Choi, Mary Ann ClarkPublisher:OpenStax
Anatomy & PhysiologyBiologyISBN:9781259398629Author:McKinley, Michael P., O'loughlin, Valerie Dean, Bidle, Theresa StouterPublisher:Mcgraw Hill Education,
Molecular Biology of the Cell (Sixth Edition)BiologyISBN:9780815344322Author:Bruce Alberts, Alexander D. Johnson, Julian Lewis, David Morgan, Martin Raff, Keith Roberts, Peter WalterPublisher:W. W. Norton & Company
Laboratory Manual For Human Anatomy & PhysiologyBiologyISBN:9781260159363Author:Martin, Terry R., Prentice-craver, CynthiaPublisher:McGraw-Hill Publishing Co.
Inquiry Into Life (16th Edition)BiologyISBN:9781260231700Author:Sylvia S. Mader, Michael WindelspechtPublisher:McGraw Hill Education
Human Anatomy & Physiology (11th Edition)
Biology
ISBN:9780134580999
Author:Elaine N. Marieb, Katja N. Hoehn
Publisher:PEARSON
Biology 2e
Biology
ISBN:9781947172517
Author:Matthew Douglas, Jung Choi, Mary Ann Clark
Publisher:OpenStax
Anatomy & Physiology
Biology
ISBN:9781259398629
Author:McKinley, Michael P., O'loughlin, Valerie Dean, Bidle, Theresa Stouter
Publisher:Mcgraw Hill Education,
Molecular Biology of the Cell (Sixth Edition)
Biology
ISBN:9780815344322
Author:Bruce Alberts, Alexander D. Johnson, Julian Lewis, David Morgan, Martin Raff, Keith Roberts, Peter Walter
Publisher:W. W. Norton & Company
Laboratory Manual For Human Anatomy & Physiology
Biology
ISBN:9781260159363
Author:Martin, Terry R., Prentice-craver, Cynthia
Publisher:McGraw-Hill Publishing Co.
Inquiry Into Life (16th Edition)
Biology
ISBN:9781260231700
Author:Sylvia S. Mader, Michael Windelspecht
Publisher:McGraw Hill Education
Biology - Intro to Cell Structure - Quick Review!; Author: The Organic Chemistry Tutor;https://www.youtube.com/watch?v=vwAJ8ByQH2U;License: Standard youtube license