- 1 How does SV40 promote cellular transformation?
- 2 How does SV40 immortalization work?
- 3 What is the role of large T antigen in SV40 pathogenesis?
- 4 What does p53 stand for?
- 5 What is SV40 promoter?
- 6 What is immortalization of cell?
- 7 What is hTERT immortalization?
- 8 What is the function of T region of SV40 viral vector?
- 9 What does an oncogene do?
- 10 What is E2F in cell cycle?
- 11 What cancers is p53 associated with?
- 12 How is p53 inactivated?
- 13 Does everyone have p53 gene?
How does SV40 promote cellular transformation?
In each case, the SV40 – transforming function correlates with the ability of one of the T antigens to bind a cellular protein. Thus, large T antigen binding to the heat shock chaperone, hsc70, the retinoblastoma family (Rb-family) of tumor suppressors, and to the tumor suppressor p53, contribute to transformation.
How does SV40 immortalization work?
For the most part, viral genes achieve immortalization by inactivating the tumor suppressor genes (p53, Rb, and others) that can induce a replicative senescent state in cells. Recent studies have also shown that SV40 T antigen can induce Telomerase activity in the infected cells.
What is the role of large T antigen in SV40 pathogenesis?
The large and small tumor antigens ( T antigens ) are the major regulatory proteins encoded by SV40. Large T antigen is responsible for both viral and cellular transcriptional regulation, virion assembly, viral DNA replication, and alteration of the cell cycle.
What does p53 stand for?
Collapse Section. The TP53 gene provides instructions for making a protein called tumor protein p53 (or p53 ). This protein acts as a tumor suppressor, which means that it regulates cell division by keeping cells from growing and dividing (proliferating) too fast or in an uncontrolled way.
What is SV40 promoter?
The early promoter of the simian virus 40 ( SV40 ) has been used as a model eukaryotic promoter for the study of DNA sequence elements and cellular factors that are involved in transcriptional control and initiation. Some of these elements are present in cellular genes, and may exhibit tissue-specificity in their action.
What is immortalization of cell?
Immortalized cells are a population of cells from a multicellular organism due to mutation, which can escape normal cellular senescence and keep undergoing division. Thus, this kind of cells can grow in vitro for prolonged periods.
What is hTERT immortalization?
Human telomerase reverse transcriptase ( hTERT )– immortalized primary cells represent a breakthrough in cell biology research that combines the in vivo nature of primary cells with the traditional cell line’s ability to survive continuously in vitro.
The function of T -antigen is controlled by phosphorylation, which attenuates the binding to the SV40 origin. Protein-protein interactions between T -antigen and DNA polymerase-alpha directly stimulate replication of the virus genome. T -antigen also binds and inactivates tumor suppressor proteins (p53, p105-Rb).
What does an oncogene do?
An oncogene is a mutated gene that contributes to the development of a cancer. In their normal, unmutated state, onocgenes are called proto- oncogenes, and they play roles in the regulation of cell division. Some oncogenes work like putting your foot down on the accelerator of a car, pushing a cell to divide.
What is E2F in cell cycle?
E2F is a group of genes that encodes a family of transcription factors (TF) in higher eukaryotes. Three of them are activators: E2F1, 2 and E2F3a. Six others act as suppressors: E2F3b, E2F4-8. All of them are involved in the cell cycle regulation and synthesis of DNA in mammalian cells.
What cancers is p53 associated with?
P53 mutations associated with breast, colorectal, liver, lung, and ovarian cancers.
How is p53 inactivated?
Paired with MDM2, also known as HDM2 in humans, the two proteins completely degrade p53 in a laboratory model. This is a process known as poly-ubiquitination, which means a specific protein completely disappears in a cell. They also did experiments on cancerous human brain tissue and found the same results.
Does everyone have p53 gene?
We just have to hope it doesn’t make the mistake in p53! In fact, these kinds of mutations can happen to anyone. Most people that get cancer actually have both of their p53 gene copies mutated, just from random chance.