Concepts of Genetics (12th Edition)
12th Edition
ISBN: 9780134604718
Author: William S. Klug, Michael R. Cummings, Charlotte A. Spencer, Michael A. Palladino, Darrell Killian
Publisher: PEARSON
expand_more
expand_more
format_list_bulleted
Concept explainers
Textbook Question
Chapter 17, Problem 24ESP
A particular type of anemia in humans, called β-thalassemia, results from a severe reduction or absence of the normal β-globin chain of hemoglobin. However, the γ-globin chain, normally only expressed during fetal development, can functionally substitute for β-globin. A variety of studies have explored the use of the nucleoside 5-azacytidine for the expression of γ-globin in adult patients with β-thalassemia.
- (a) How might 5-azacytidine lead to expression of γ-globin in adult patients?
- (b) Explain why this drug may also have some adverse side effects.
Expert Solution & Answer
Want to see the full answer?
Check out a sample textbook solutionStudents have asked these similar questions
A particular type of anemia in humans, called b-thalassemia,results from a severe reduction or absence of the normal b-globinchain of hemoglobin. However, the g@globin chain, normally onlyexpressed during fetal development, can functionally substitutefor b-globin. A variety of studies have explored the use of thenucleoside 5-azacytidine for the expression of g-globin in adultpatients with b-thalassemia.(a) How might 5-azacytidine lead to expression of g-globin inadult patients?(b) Explain why this drug may also have some adverse side effects.
The proximal histidine residues have been replaced by glycine residues by mutation of the cloned genes for both the α and β subunits of hemoglobin. With the tetrameric mutant hemoglobin (all subunits being mutant, α H F8 G, β H F8 G), it was found that the “proximal” coordination bonds to hemes in the mutant protein could be replaced by having the small molecule imidazole in the buffers. Oxygen binding curves for the tetrameric mutant hemoglobin were measured.
A. The degree of cooperativity in oxygen binding for the mutant hemoglobin (with imidazole present) would be expected to
1) increase 2) decrease 3) not be affected)
compared with the normal protein.
B. Justify your answer to part A in terms of what you know about the structural basis of cooperativity in hemoglobin.
C. How would the Hill coefficient for the mutant be expected to change compared with nH for normal hemoglobin, which is ~3?
The codon change (Gly-12 to Val-12) in human rasH that convertsit to oncogenic rasH has been associated with many types ofcancers. For this reason, researchers would like to develop drugs toinhibit oncogenic rasH. Based on your understanding of the Rasprotein, what types of drugs might you develop? In other words,what would be the structure of the drugs, and how would theyinhibit Ras protein? How would you test the efficacy of the drugs?What might be some side effects?
Chapter 17 Solutions
Concepts of Genetics (12th Edition)
Ch. 17 - Cancer cells often have abnormal patterns of...Ch. 17 - The hormone estrogen converts the estrogen...Ch. 17 - Each year in the United States, there are over...Ch. 17 - Prob. 2CSCh. 17 - Each year in the United States, there are over...Ch. 17 - HOW DO WE KNOW? In this chapter, we focused on how...Ch. 17 - CONCEPT QUESTION Review the Chapter Concepts list...Ch. 17 - What features of eukaryotes provide additional...Ch. 17 - Provide a definition of chromatin remodeling, and...Ch. 17 - Describe the organization of the interphase...
Ch. 17 - A number of experiments have demonstrated that...Ch. 17 - Provide a brief description of two different types...Ch. 17 - Present an overview of the manner in which...Ch. 17 - Prob. 9PDQCh. 17 - Explain how the addition of acetyl groups to...Ch. 17 - Distinguish between the cis-acting regulatory...Ch. 17 - Prob. 12PDQCh. 17 - Describe the manner in which activators and...Ch. 17 - Compare the control of gene regulation in...Ch. 17 - Many promoter regions contain CAAT boxes...Ch. 17 - Prob. 16PDQCh. 17 - Prob. 17PDQCh. 17 - Many transcriptional activators are proteins with...Ch. 17 - Prob. 19PDQCh. 17 - DNA supercoiling, which occurs when coiling...Ch. 17 - Prob. 21ESPCh. 17 - Prob. 22ESPCh. 17 - Because the degree of DNA methylation appears to...Ch. 17 - A particular type of anemia in humans, called...Ch. 17 - Regulation of the lac operon in E. coli (see...Ch. 17 - DNA methylation is commonly associated with a...Ch. 17 - During an examination of the genomic sequences...Ch. 17 - Prob. 28ESPCh. 17 - Although a single activator may bind many...Ch. 17 - Hereditary spherocytosis (HS) is a disorder...Ch. 17 - Transcription factors play key roles in the...
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 protein encoded by the cystic fibrosis gene is 1480amino acids long, yet the gene spans 250 kb. How is thisdifference possible?arrow_forwardThe Na'vi of Pandora have a neuronal gene (Na'vi) product that undergoes extensive post-translational processing that produces several protein products with a variety of tissue-specific expression patterns, cellular locations, and functions. Mutations that affect Na'vi expression, sorting, processing and function in specific neurons have been linked to altered skin color and height in Na'vi. Propose a mechanism by which: 1. The protein products of Na'vi can be tissue specific. 2. Na'vi can be processed and targeted to secretory vesicles.arrow_forwardThe lac genotypes are as shown below: P+OcZ-Y+A+// P¯O+Z+Y+A+ (i) The lac operon consists of three structural genes, lacZ, lacY and lacA. Which structural genes are involved in lactose metabolism? Explain. (ii) Draw and explain how lactose repress the gene expression in lac IS/I- heterozygote. (iii) What is the function of the promoter in the bacterial operon?arrow_forward
- Describe how polymorphisms is found at 13910-C/T and 22018-G/A in the regulatory area of the lactase gene (LCT). And elaborate the mechanism for two polymorphisms causing mutation from 13910-C/T and 22018-G/A to 13910-C/C or 22018-G/G variants in lactase intolerance disorder. also, how LCT gene is corelated to lactase intolerance disorder?arrow_forwardIn one type of hemoglobin variant, lysine EF6 is replaced by an aspartic acid residue. What would be the effects of this mutation on the affinity of the hemoglobin for 2,3 BPG and oxygen? The affinity for 2,3-BPG would increase, and for oxygen would decrease. The affinity for 2,3-BPG would decrease, and for oxygen would decrease. The affinities for 2,3-BPG and for oxygen would be unaffected. The affinity for 2,3-BPG would increase, and for oxygen would increase. The affinity for 2,3-BPG would decrease, and for oxygen would increase.arrow_forwardCTP synthetase catalyzes the glutamine-dependent conversion of UTP to CTP. The enzyme is allosterically inhibited by the product, CTP. Mamma- lian cells defective in this allosteric inhibition are found to have a complex phenotype: They require thymidine in the growth medium, they have unbal- anced nucleotide pools, and they have an elevated spontaneous mutation rate. Explain the likely basis for these observations.arrow_forward
- Lewis Blood Group System is a human blood group unlike most others. The antigen is produced and secreted by exocrine glands, eventually adsorbing to the surface of red blood cells. Its expression is based on the genetic expression of the Lewis and Secretor genes. Based on the following genotype (Le) (sese), what would you predict the Lewis antigen phenotypic expression to be?arrow_forwardConsider the mechanism of the enzyme RNase: What would happen to the Km (i.e., would it increase, decrease, or stay the same) if the his12 was mutated to a lysine? Explain. What would happen to the Kcat (i.e., would it increase, decrease, or stay the same) if the his12 was mutated to a valine? Explain.arrow_forwardAurora AAurora A is a protein that acts as a kinase (transfers phosphates to molecules). Many types of cancer cells, including breast cancer cells, have higher than normal levels of this protein.Expressions of Aurora A genes in normal breast tissues (n = 10), normal tissues adjacent to tumors (n = 12) and breast tumors (n = 14).Scientists studying the production of Aurora A protein in normal frog cells observed that the amount of this protein in the cells changed throughout the cell cycle.Scientists tested chemicals that block Aurora 2 to see if they could be used as anti-cancer drugs. They found that some of the candidate drugs did slow the growth of cancer cells in cell culture in the lab. But when they tested these drugs in cancer patients to see if the drugs could slow the growth of solid tumors, they found that the benefit to patients was small when compared to the development of severe side effects such as anemia (low red blood cell count) and leukopenia (low white blood cell…arrow_forward
- Mutations in the IL2RG gene cause approximately 30 percent of severe combined immunodeficiency disorder (SCID) cases in humans. These mutations result in alterations to a protein component of cytokine receptors that are essential for proper development of the immune system. The IL2RG gene is composed of eight exons and contains upstream and downstream sequences that are necessary for proper transcription and translation. Below are some of the mutations observed. For each, explain its likely influence on the IL2RG gene product (assume its length to be 375 amino acids). (a) Nonsense mutation in a coding region (b) Insertion in Exon 1, causing frameshift (c) Insertion in Exon 7, causing frameshift (d) Missense mutation (e) Deletion in Exon 2, causing frameshift (f) Deletion in Exon 2, in frame (g) Large deletion covering Exons 2 and 3arrow_forwardCTP synthetase catalyzes the glutamine-dependent conversion of UTP to CTP. The enzyme is allosterically inhibited by the product, CTP. Mammalian cells defective in this allosteric inhibition are found to have a complex phenotype: They require thymidine in the growth medium, they have unbalanced nucleotide pools, and they have an elevated spontaneous mutation rate. Explain the likely basis for these observations.arrow_forwardIn this chapter you were introduced to nonsense suppressor mutations in tRNA genes. However, suppressormutations also occur in protein-coding genes. Using thetertiary structure of the β subunit of hemoglobin shownin Figure 9-3(c), explain in structural terms how a mutation could cause the loss of globin protein function. Nowexplain how a mutation at a second site in the same protein could suppress this mutation and lead to a normalor near-normal protein.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:PEARSONBiology 2eBiologyISBN:9781947172517Author:Matthew Douglas, Jung Choi, Mary Ann ClarkPublisher:OpenStaxAnatomy & 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 & CompanyLaboratory 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
Mitochondrial mutations; Author: Useful Genetics;https://www.youtube.com/watch?v=GvgXe-3RJeU;License: CC-BY