#Question id: 4534
#Unit 3. Fundamental Processes
The yeast Saccharomyces cerevisiae divides by budding: instead of dividing to produce two identical daughter cells, the so-called mother cell buds to produce a daughter cell, The HO gene is expressed only in mother cells and only at a certain point in the cell cycle,
1. SBF |
I- Which is active only during the G1-S transition of the cell cycle. |
2. SWI5 |
II-Which acts only in the mother cell. |
III- Recruit nucleosome modifiers |
#Question id: 4535
#Unit 3. Fundamental Processes
The activators bind—and the enhanceosome forms—in a highly cooperative manner, ensuring that all three activators must be present. The following are three ways the regulators might be binding cooperatively:
I- Through direct protein–protein interactions between them
II- By changes in the DNA caused by binding of one protein helping binding of another;
III- By the fact that the activators all interact simultaneously with the coactivator.
#Question id: 4536
#Unit 3. Fundamental Processes
The human b-interferon gene is activated in cells upon viral infection through some activators, EXCEPT one
#Question id: 4537
#Unit 3. Fundamental Processes
The enhancer DNA is __, but once the activators are bound it is relatively , HMGA1 the DNA and thus helps the final structure form.
#Question id: 4538
#Unit 3. Fundamental Processes
We first consider a generic case. Gene A is controlled by four signals (1, 2, 3, and 4), each working through a separate activator (activators 1, 2, 3, and 4). Gene B is controlled by three signals (3, 5, and 6), working through activators 3, 5, and 6. It shows-
#Question id: 4539
#Unit 3. Fundamental Processes
The yeast S. cerevisiae exists in three forms: two haploid cells of different mating types—a and alpha and the diploid formed when an a and an a cell mate and fuse. The a cell and the a cell each encodes cell-type-specific regulators: a cells make the regulatory protein a1, and alpha cells make the proteins alpha1 and alpha2. A fourth regulatory protein, called Mcm1, is also involved in regulating the mating-type-specific genes (and many other genes) and is present in both cell types which shows Combinatorial Control.
The arrangement of regulators at the promoters of a-specific genes and a-specific genes is
cell type: |
gene regulatory proteins: |
target genes: |
1.a cell (haploid) |
a1 Mcm1 |
aSG alphaSG |
2.αlpha cell (haploid) |
alpha 1 alpha 2 Mcm2 |
hSG |
3.a/αlpha cell (diploid) |
a1 Mcm2 alpha2 |