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.

Aurora 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…

Consider 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.

Mutation in the fibroblast growth factor receptor (FGFR) gene results in achondroplasia (dwarfism), which is a dominant condition caused by a single base substitution (GGG>AGG) that changes the amino acid glycine at position 480 to arginine (G480R) in the FGFR protein. FGFR is normally active when FGF binds to it, but the mutant FGFR is always on to stimulate signaling that inhibits excessive bone growth. How can gene therapy be used to treat achondroplasia? Select all that apply. RNAi that knocks down the mutant FGFR expression Adeno-associated viral (AAV) vector that carries the wild-type FGFR Retroviral vector that carries the wild-type FGFR CRISPR with the wild-type FGFR donor DNA

If you were given a tube containing only a purified protein of interest but had unlimited time and resources, how would you determine the in vivo expression levels of that protein? Is there another level of regulation beyond the protein expression level which might not be observable with the method you described?

During periods of sustained demand and in the presence of sufficient nutrients, muscle cells can increase in size. When the size of muscle cells increases, they will often develop additional nuclei in their intracellular environment. Which of the following is the most likely explanation for the expression of additional nu- clei in growing muscle cells? A B с D Nutrients entering the cells will be digested and recycled more quickly by the additional nuclei to better support the subcellular components in the cell as its size increases. The ATP molecules that are produced in the additional nuclei will be able to better sup- port the increased energetic demands on the muscle cell as its size increases. The addition of more nuclei to the cell will allow more genetic information to be stored in the cell and allow the cell to produce additional types of proteins as its size increases. Additional nuclei allow subcellular components to continue to be sufficiently expressed and transferred…

CD3 is a signaling protein that is typically found only in the plasma membrane of immune system T lymphocytes. CD3 is composed of several different polypeptides, including a gamma chain, CD3γ. Scientists analyzed the promoter of the CD3γ chain gene for regulatory sequences that might have positive or negative effects on expression of the gene. The scientists cloned fragments of the CD3γ gene that included the first transcribed nucleotides plus up to 789 nucleotides of upstream regulatory sequences into plasmids in which the gene for the firefly enzyme luciferase immediately follows the fragments. The plasmids were then introduced into a line of T lymphocytes (Figure 1), and the cells were allowed to grow for a short while. Because the regulatory sequences of the CD3γ gene immediately precede the luciferase gene in the plasmids, the activity, either positive or negative, of the regulatory sequences affected the amount of luciferase gene expression by the T lymphocytes. Luciferase…