45
complementary bases (in the opposite strand), and a conformational and abnormal
change occurs to the DNA molecule. This distortion in the DNA molecule can
inhibit DNA synthesis (process called DNA replication) and other important cellular events (Roy 2017). In addition, UV radiation can cause DNA damage indirectly,
by generating high intracellular concentrations of reactive oxygen species as a consequence of the cellular stress response (Roy 2017; Griffiths et al. 1998).
4.2.2.2 DNA Damage Response After UV Radiation
Aforementioned, the DNA’s sequence must be kept unchanged in order to guarantee
accurate transfer of genetic information to cell progeny. Therefore, DNA lesions
generated by UV rays are a serious threat for the cell and must be repaired in order
to prevent defective genetic material. Fortunately, cells have developed a complex
and very dynamic network known as DNA damage response (DDR) which deal
Fig. 4.3 Thymine dimers. UV radiation induces a link (covalent link) between two adjacent thymines present in the same strand of the DNA molecule. According to the position of the link, two
different dimers can be formed: cyclobutane pyrimidine dimers (CPDs) or 6–4 pyrimidinepyrimidone adducts (6–4 PPs)
4 SDG 3 Good Health and Well-Being
complementary bases (in the opposite strand), and a conformational and abnormal
change occurs to the DNA molecule. This distortion in the DNA molecule can
inhibit DNA synthesis (process called DNA replication) and other important cellular events (Roy 2017). In addition, UV radiation can cause DNA damage indirectly,
by generating high intracellular concentrations of reactive oxygen species as a consequence of the cellular stress response (Roy 2017; Griffiths et al. 1998).
4.2.2.2 DNA Damage Response After UV Radiation
Aforementioned, the DNA’s sequence must be kept unchanged in order to guarantee
accurate transfer of genetic information to cell progeny. Therefore, DNA lesions
generated by UV rays are a serious threat for the cell and must be repaired in order
to prevent defective genetic material. Fortunately, cells have developed a complex
and very dynamic network known as DNA damage response (DDR) which deal
Fig. 4.3 Thymine dimers. UV radiation induces a link (covalent link) between two adjacent thymines present in the same strand of the DNA molecule. According to the position of the link, two
different dimers can be formed: cyclobutane pyrimidine dimers (CPDs) or 6–4 pyrimidinepyrimidone adducts (6–4 PPs)
4 SDG 3 Good Health and Well-Being