Can you figure a way in which the hTR RNA was isolated and shown to be a part of the holoenzyme complex?
RNA was isolated from the subsequent immune complexes by phenol/chloroform extraction and subjected to RT–PCR for the presence of hTR, or β2M mRNA as a control.
Human telomerase RNA (hTR) is transcribed as a precursor that is then posttranscriptionally modified and processed. A fraction of the transcripts is oligoadenylated by TRAMP and either processed into the mature hTR or degraded by the exosome.
Human telomerase acts on telomeres during the genome synthesis phase of the cell cycle, accompanied by its concentration in Cajal bodies and transient colocalization with telomeres. Whether the regulation of human telomerase holoenzyme assembly contributes to the cell cycle restriction of telomerase function is unknown. We investigated the steady-state levels, assembly, and exchange dynamics of human telomerase subunits with quantitative in vivo cross-linking and other methods. We determined the physical association of telomerase subunits in cells blocked or progressing through the cell cycle as synchronized by multiple protocols. The total level of human telomerase RNA (hTR) was invariant across the cell cycle. In vivo snapshots of telomerase holoenzyme composition established that hTR remains bound to human telomerase reverse transcriptase (hTERT) throughout all phases of the cell cycle, and subunit competition assays suggested that hTERT-hTR interaction is not readily exchangeable. In contrast, the telomerase holoenzyme Cajal body-associated protein, TCAB1, was released from hTR in mitotic cells coincident with TCAB1 delocalization from Cajal bodies. This telomerase holoenzyme disassembly was reversible with cell cycle progression without any change in total TCAB1 protein level. Consistent with differential cell cycle regulation of hTERT-hTR and TCAB1-hTR protein-RNA interactions, overexpression of hTERT or TCAB1 had limited if any influence on hTR assembly of the other subunit. Overall, these findings revealed a cell cycle regulation that disables human telomerase association with telomeres while preserving the co-folded hTERT-hTR ribonucleoprotein catalytic core. Studies here, integrated with previous work, led to a unifying model for telomerase subunit assembly and trafficking in human cells.
Can you figure a way in which the hTR RNA was isolated and shown to be...
1. Suppose that you isolated an enveloped icosahedral RNA virus. Purified RNA from this virus is capable of supporting translation in a rabbit reticulocyte cell‑free translation systemor in any other such system. Further analysis indicates that this virus replication is not inhibited by actinomycin D, a strong inhibitor of DNA-dependent RNA polymerase.Based on this information, discuss the mechanism by which this virus replicates its genome in infected susceptible, permissive cells. 2. Suppose that you isolated an enveloped helical RNA virus. Purified...
Suppose that you isolated an enveloped helical RNA virus. Purified RNA from this virus is capable of supporting translation in a rabbit reticulocyte cell-free translation system or in any other such system. Further analysis indicates that this virus replication is inhibited if infected cells are incubated with protease inhibitor such as trypsin inhibitor. Based on this information, discuss the mechanism by which this virus replicates its genome in infected susceptible, permissive cells.
Which of the following statements about RNA is NOT TRUE? a) RNA can catalyze reactions b) RNA can adopt complex tertiary structures c) RNA nucleotides can partake in Watson-Crick base pairing d) RNA nucleotides can partake in nonstandard base pairing e) All of the above are true
Which phase of transcription is shown in the figure below? Completed RNA transcript Initiation Termination Disengagement Elongation
Part
A
The sigma (?) subunit binds to the core RNA polymerase
enzyme. The function of this sigma factor is to recognize and bind
to the promoter of a gene so that transcription can be initiated.
The closeup shows the secondary structure of the sigma (?)
subunit, which consists of four domains. Identify the domains
labeled 1-3.
The sigma (?) subunit binds to the core RNA polymerase
enzyme. The function of this sigma factor is to recognize and bind
to...
Which is the product that can be isolated from the reaction shown? C.HNHNH н (A) (B) NH CH-NHCKH NNHCH CH (C) он (D) NH CH-NHCH
Given the dna template shown in the figure below which of the following bases would you find in a complementary RNA stand and where in the cell would they be synthesired?
In the circuit shown in (Figure 1) all meters are idealized and the batteries have no appreciable Internal resistance. For related problem solving tips and strategies, you may want to view a Video Tutor Solution of A complex network. Part B Find the reading of the voltmeter with the switch S open. PartC With the switch closed, find the reading of the voltmeter. Part D With the switch closed, find the reading of the ammeter. Part E Which way (up or down) does the curent fiow through the switch?
Can someone please help with these two questions? Thank you.
4. Here is an RNA transcript freshly transcribed from a gene. It is immature, meaning that it has not been processed yet into a mature mRNA. a) If you could zoom in on this molecule, what two things would you observe at the molecular level that would indicate to you that it is RNA and not DNA? b) Which end of the molecule was the last bit to be transcribed,...
B3. An octahedral transition metal complex with the structure shown below was isolated from the reaction of CoCl2.6H20 and one equivalent of the organic ligand diethylenetriamine, H2NCH2CH2NHCH2CH2NH2, after oxidation with air and addition of Naci. I-Z H2N,,, NH2 com CICI a) Draw the structure for a different geometric isomer of the product which may also form from the same reaction, AND label the complex you have drawn with an appropriate stereochemical descriptor. The complex shown on the previous page is...