You are a researcher at a small biotech company and your company has just obtain
ID: 179251 • Letter: Y
Question
You are a researcher at a small biotech company and your company has just obtained the license for use of a human GENOMIC DNA fragment putatively encoding a potentially novel protein, which is thought to regulate p53, the known tumor supressor protein. The scientists who originally cloned this GENE fragment HDM5 "claim" that HDM5 shares 90% DNA sequence homology with one of the HDM2 genes (refer to the review Levine & Oren, 2009). They propose that HDM5 may have HDM2-like properties and may be involved in regulating cell proliferation, and thus a good target to potentially develop as a cancer therapy. Your company has asked you to characterize the gene and gene products, as well as to provide an opinion as to its potential human therapeutic uses.
1. Your gene would need to be transcriptionally active in order for mRNA to be transcribed. A transcriptionally active gene compared with a transcriptionally INactive gene would be expected to (you may choose more than one of the following):
a. contain acteylated histones
b. contain unacetylated histones.
c. be sensitive to DNase I.
d. be resistant to DNase I.
Explain why you selected, or did not select, each option.
Explanation / Answer
Answer: A transcriptionally active chromatin/DNA are expected to contain acetylated histones and are sensitive to DNase I.
Histone acetylations are a kind of epigenetic mechanism that regulates the gene expression in eukaryotes. Acetylations of histones by histone acetyltranferases decreases the affinity of histones for DNA and makes them transcriptionally active as it is releived from histones which makes the releived DNA accessaable to transcriptional machinery.
DNase 1 is an endonuclease acts on the chromatin which has lost its condensed structure because of histone acetylation and become more accessable to DNase I activity which otherwise been protected by histones..
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.