The Role of Adenovirus Protein in the DNA-PK-dependent DNA Damage Response
Faculty Mentor(s) Name(s)
Dr. Kasey Karen
Abstract
Adenovirus serotype 5 (Ad5) is a double-stranded (ds) DNA virus that causes upper respiratory infections and conjunctivitis. The Ad5 viral genome can be broken down into 5 early and 5 late regions. An important viral protein of the E4 region, E4 11k, aids in the manipulation shutdown of host cell machinery to allow for viral replication by stimulating late mRNA splicing and preventing the inhibition of viral DNA replication. One mechanism is through the inhibition of the DNA damage response (DDR). Part of the DDR is responsible for repairing double-stranded DNA breaks (DSBs) through non-homologous end joining. DNA-dependent protein kinase (DNA-PK) facilitates this type of DSB repair and activates further DDR. During an infection, Ad5’s linear dsDNA genome triggers the DSB repair pathway. DDR tries to “repair” the viral genome resulting in the concatenation and inactivation of the virus. Ad5, however, has evolved mechanisms to prevent the DDR from functioning normally, allowing effective infection. Previously, E4 proteins have been shown to regulate the activation of DNA-PK by autophosphorylation. In this study, we aim to determine if E4 11k can inhibit DNA-PK activation. To determine if E4 11k can inhibit DNA-PK activation, wWe pre-treated HeLa (cervical cancer) cells with E4 11k or, Nu7441 (a known DNA-PK activation inhibitor) treatment and then induced DSBs with the chemotherapy drug, etoposide. We then analyzed DNA-PK activation based on the level of phosphorylation by Western blotting. To induce DSBs, we used the chemotherapy drug, etoposide. It has also been shown that etoposide treatment and DNA-PK activation inhibition result in cancer cells becoming less adherent and remove their ability to repair the DNA damage. These findings suggest a potential mechanism for which E4 11k can be used as a novel chemosensitizer for therapy-resistant cancer cells.
Start Date
27-3-2024 10:00 AM
End Date
27-3-2024 10:08 AM
Location
Arts and Sciences 2-70
The Role of Adenovirus Protein in the DNA-PK-dependent DNA Damage Response
Arts and Sciences 2-70
Adenovirus serotype 5 (Ad5) is a double-stranded (ds) DNA virus that causes upper respiratory infections and conjunctivitis. The Ad5 viral genome can be broken down into 5 early and 5 late regions. An important viral protein of the E4 region, E4 11k, aids in the manipulation shutdown of host cell machinery to allow for viral replication by stimulating late mRNA splicing and preventing the inhibition of viral DNA replication. One mechanism is through the inhibition of the DNA damage response (DDR). Part of the DDR is responsible for repairing double-stranded DNA breaks (DSBs) through non-homologous end joining. DNA-dependent protein kinase (DNA-PK) facilitates this type of DSB repair and activates further DDR. During an infection, Ad5’s linear dsDNA genome triggers the DSB repair pathway. DDR tries to “repair” the viral genome resulting in the concatenation and inactivation of the virus. Ad5, however, has evolved mechanisms to prevent the DDR from functioning normally, allowing effective infection. Previously, E4 proteins have been shown to regulate the activation of DNA-PK by autophosphorylation. In this study, we aim to determine if E4 11k can inhibit DNA-PK activation. To determine if E4 11k can inhibit DNA-PK activation, wWe pre-treated HeLa (cervical cancer) cells with E4 11k or, Nu7441 (a known DNA-PK activation inhibitor) treatment and then induced DSBs with the chemotherapy drug, etoposide. We then analyzed DNA-PK activation based on the level of phosphorylation by Western blotting. To induce DSBs, we used the chemotherapy drug, etoposide. It has also been shown that etoposide treatment and DNA-PK activation inhibition result in cancer cells becoming less adherent and remove their ability to repair the DNA damage. These findings suggest a potential mechanism for which E4 11k can be used as a novel chemosensitizer for therapy-resistant cancer cells.