DNA repair mechanism

What molecule is used as a template for repairing damaged DNA in the following processes?

a) Base-excision repair

 b) Photoreactivation repair

c) Nucleotide excision repair

d) Homologous recombination repair

e) Non-homologous end-joining

The answer would be 

(a) DNA glycosylases

(b) DNA photolyases

(c) DNA polymerase

(d) RPA protein

(e) microhomologies

Read More

Unknown Thursday, March 13, 2014  No comment

How does a mutation in BRCA1 gene that leads to an impairment of double-strand DNA repair affect cell’s response to cancer?

BRCA1 gene belongs to a class of genes known as tumor suppressor genes protein from the BRCA1 gene helps prevent cells from growing and dividing too rapidly

This gene produce a protein that is directly involved in repairing damaged DNA. In the nucleus of many types of normal cells, the BRCA1 protein interacts with several other proteins, including the proteins produced from the RAD51 and BARD1 genes, to mend breaks in DNA. These breaks can be caused by natural and medical radiation or other environmental exposures, and also occur when chromosomes exchange genetic material in preparation for cell division. By helping repair DNA, BRCA1 plays a role in maintaining the stability of a cell's genetic information.


So if a mutation in BRCA1 occurs the breaks in DNA can't be fixed and response to cancer affected

Read More

Unknown Monday, December 23, 2013  No comment