The effect of TRAP150 on HPV16 E1 gene regulation

Sammanfattning: Human papilloma virus (HPV) is a small DNA virus that is known as the causative agent in cervical cancer. The virus is found worldwide and causes more than 300 000 deaths yearly. Although there are many types of HPV, HPV16 is found in 99 % of cervical cancer cases. There are several vaccines available but as of now there is no antiviral treatment for the disease. Thus, it is further studies are required to find potential targets or biomarker which can be used to develop new treatments. The viral genome is divided into early and late genes. Where the early genes are active during the early stage of infection and the late genes are upregulated at the late stage of infection. The early (E) genes E6 and E7 are oncogenic. E6 prevents the cells from going into apoptosis and E7 drives proliferation. The E1 and E2 genes are involved in the replication of the viral genome. The HPV16 genome is polycistronic, meaning that the mRNAs that the virus produces encodes for several proteins. Gene regulation is thus very important for the virus. The HPV only have two promoters which means that it has to utilize other methods to control its gene expression. It uses alternative splicing to control the expression of its genes. Using different splice sites the virus can produces many different pre-mRNAs. The splice sites are in turn controlled by regulatory elements called enhancers and silencers. These elements acts as binding places for cis-acting elements (RNA) and trans-acting factors (protein).   This report focuses on the regulation of the E1 gene. It investigates whether the trans-acting factor TRAP150 affects the regulation of the E1 gene. Using reporter plasmids to with a reporter Luciferase gene the expression of the gene can be studied.   The results indicate that TRAP150 does induce splicing of E1, although it is not clear how it does this. It also seems that the splicing variant E1C upregulated by the presence of TRAP150. Using deletion mutants to study the TRAP150 interaction, it was also found that the N-terminal is essential for splicing to happen. This also concurs with previously reported results.