To review:
The reason for the failure of a transcriptionally active fusion gene to cause chronic myelogenous leukemia (CML) in healthy individuals.
Introduction:
Chronic myelogenous leukemia is a type of cancer of the white blood cells (WBCs). In this form of leukemia, an increased and unregulated growth of the immature myeloid cells occurs in the bone marrow. This is followed by the accumulation of these proliferated cells in the blood and spleen. The characteristic genetic change responsible for this disease is a chromosomal translocation that leads to the formation of Philadelphia chromosome that contains the Breakpoint cluster region (BCR) and Abelson murine leukemia (ABL) genes to form a fusion protein, this protein is responsible for the failure of cell cycle control.
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Study Guide and Solutions Manual for Essentials of Genetics
- Can you please help me by drawing a serie of schematic figures that demonstrates the information in the paragraph below. The carboxy terminus of the p53 protein acts as an allosteric regulator of sequence-specific DNA binding. This was demonstrated initially by Hupp et al. (1992) using a bacterially expressed protein. Recombinant bacterial p53 bound poorly to DNA, and binding could be enhanced by the addition of antibodies specific to the C-terminal region of the protein. Phosphorylation of Ser315 and Ser392 within this domain also enhance sequence-specific DNA binding. Dephosphorylation of Ser376 of p53 after IR allows the association of 14-3-3 proteins with the C terminus of the protein (Waterman et al., 1998). Stavridi et al. (2001) demonstrate that this interaction is required for p53 to activate the downstream gene, p21waf1/cip1, and for the G1 cell cycle checkpoint arrest response. Interestingly, this dephosphorylation event seems to be ATM-dependent, possibly by a phosphatase…arrow_forwardTransformation is a process in which bacteria take up new DNA released by dead cells and integrate it into their own genomes (see p. 265 in Chapter 9). In Streptococcus pneumoniae (which causes many cases of pneumonia, inner-ear infections, and meningitis), the ability to carry out transformation requires from 105 to 124 genes, collectively termed the com regulon. The com regulon is activated in response to a protein called competence-stimulating peptide (CSP), which is produced by the bacteria and exported into the surrounding medium. When enough CSP accumulates, it attaches to a receptor on the bacterial cell membrane, which then activates a regulator protein that stimulates the transcription of genes within the com regulon and sets in motion a series of reactions that ultimately result in transformation. Does the com regulon in Streptococcus pneumoniae exhibit positive or negative control? Explain your answer.arrow_forwardIn the experiment summarized below, scientists were examining the presence of specific sequences in individuals with age. In this experiment they extracted DNA from lymphocytes of various aged individuals and measured the length of a TTAGGG (in kb) repeat they found in their genomic DNA (Left Panel). In the right panel, the scientists measured the length of the same repeats in individuals with lymphocyte failure (red dots most severely effected) that have a mutation in a critical enzyme. Answer the following questions in 2-3 sentences each. A. What is the name of the specific sequence the scientists are measuring in the experiment shown below. B. For the individuals with lymphocyte pathology in the right panel, which gene is likely defective that causes the data shown? C. Explain why the length of the repeat sequence decreases with age.arrow_forward
- You identify a mouse mutant that has hemophilia and is unable to properly clot blood. Your assays reveal that a novel clotting factor is absent from the blood of the mutant mice. You sequence the genome of the mutant mouse and determine that clotting factor proteins normally associated with hemophilia are all wildtype (no mutations), but the coding sequence of the novel protein differs by one amino acid compared to wildtype. When you synthesize the mutant protein in vitro, it has normal blood clotting activity. Your controls using other mutant hemophilia clotting proteins fail to clot blood in this assay. What would you say the mutant protein results in hemophelia?arrow_forwardThe genetic alteration responsible for sickle-cell anemia in humans involves: a transition mutation from A to G, substituting glutamic acid for valine in a-globin a transversion mutation from T to A, substituting valine for glutamic acid in b-globin a transition mutation from T to C, substituting valine for glutamic acid in b-globin a transversion mutation from G to C, substituting glutamic acid for valine in a-globin a frameshift mutation of one ATC codon, removing glutamic acid from b-globinarrow_forwardBRCA1 is mutated in a large percentage of hereditary breast and ovarian cancers. BRCA1 protein serves as a key enzyme in repairing DNA double-strand breaks. More than 800 mutations in the BRCA1 are clinically significant. This collection of mutations include missense mutations, small deletions, and large rearrangements that result in a protein with reduced function or no protein product. BRCA1 functions by interacting with a variety of proteins, such as Rb, Myc, cyclin-dependent kinase (CDK), and Rad50/51. Rb is important for cell cycle arrest; Myc is a transcription factor that activates genes required for cell proliferation; activated CDK promotes cell cycle progression; and Rad50/51 proteins facilitate repair of DNA double-strand breaks. How many of the mutations listed below would lead to excessive cell growth when the cell was either homozygous or heterozygous for the mutation? Increased expression of Myc Constitutively active Rad50/51 A null mutation in Rb Continuous production…arrow_forward
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- Human Heredity: Principles and Issues (MindTap Co...BiologyISBN:9781305251052Author:Michael CummingsPublisher:Cengage Learning