Question

What is the relationship between proto-oncogenes and oncogenes?

Answer 1

Answer:

Oncogenes result from a mutation in  proto-oncogenes.

Explanation:

• Protooncogenes control the growth and division of cells.
• The proteins encoded by proto-oncogenes include growth factors, growth factor receptors, transcription factors and signal transducers.
• They contribute to the transformation process by driving cell proliferation or reducing sensitivity to cell death.
• Several types of genetic and epigenetic changes convert these proto-oncogenes to oncogenes.
• Oncogenes arise due to the changes that increases the expression of proto-oncogenes .
• Oncogenes are one of the causes of cancers.

A proto-oncogenes can turn into oncogene by following ways:

• A point mutation  such as deletion, insertion and substitution  in the proto-oncogene can lead to formation of oncogenes.
• Chromosomal translocation may result in activation of proto-oncogene as seen in Burkitt's lymphoma.
• Insertion of a mobile genetic material such as retrovirus changes the gene expression, but leaves their coding sequence intact.
• Activation of proto-oncogene can also occur from reduplication and amplification of DNA sequence.