Select true ‘T’ AND false ‘F’ about ubiquitinylation

I. These ubiquitin-like modifiers control processes as diverse as nuclear import,

II. Regulated by the ubiquitin-like modifier Sumo, and autophagy,

III. Regulated by the ubiquitin-like modifier Atg8.

IV. For a protein to be efficiently degraded, it must be linked to a chain of at least four tandemly linked ubiquitin molecules in which Lys 34 of each ubiquitin forms an isopeptide bond with the C-terminal carboxyl group of the following ubiquitin.

#Question id: 4514

#Unit 3. Fundamental Processes

What is true about coactivators,

A. The coactivators act directly by binding to the DNA

B. The coactivators act indirectly—not by binding to the DNA

C. Are required for essential communication between the activators and the complex composed of Pol II.

D. Are required for essential communication between the and the basal (or general) transcription factors.

#Question id: 4515

#Unit 3. Fundamental Processes

Transcription Activators are,

A. Known to facilitate transcription at hundreds of promoters,

B. Specific for a few promoters,

C. Sensitive to the binding of signal molecules,

D. Providing the capacity to activate or deactivate transcription in response to a changing cellular environment.

#Question id: 4516

#Unit 3. Fundamental Processes

High mobility group (HMG) proteins

A. are a common type of architectural regulator

B. facilitating the looping of the DNA

C. the binding is relatively very specific

D. are abundant in chromatin and bind to DNA with limited specificity.

#Question id: 4517

#Unit 3. Fundamental Processes

Statement: When phosphorylated, CREB binds to CREs near certain genes and acts as a transcription factor, turning on the expression of these genes.

Explanation: I-Regulation can result from phosphorylation of Nuclear transcription factor

II- Activation of a protein kinase in the nucleus that phosphorylates specific DNA-binding proteins and thereby alters their ability to act as transcription factors.

#Question id: 4518

#Unit 3. Fundamental Processes

The sequence of transcriptional activation events at a typical Pol II promote

I- Mediator facilitates the binding of TBP (or TFIID) and TFIIB, and the other basal transcription factors and Pol II then bind.

II- Activators bind the DNA.

III-The activators recruit the histone modification/nucleosome remodeling complexes and a coactivator such as Media.

IV- Phosphorylation of the carboxyl-terminal domain (CTD) of Pol II leads to transcription initiation.

#Question id: 4519

#Unit 3. Fundamental Processes

Some steroid hormone receptors function in the nucleus as transcription activators, stimulating the transcription of certain genes when a particular steroid hormone signal is present. When the hormone is absent, the receptor proteins revert to a repressor conformation, preventing the formation of PICs. It is an example of;