CPD and 6-4PP photolyases expression by messenger RNA transfection in DNA repair deficient cells

• Grant number: 23/12825-6
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: November 01, 2023
• End date: October 31, 2025
• Field of knowledge: Biological Sciences - Genetics - Mutagenesis
• Agreement: Netherlands Organisation for Scientific Research (NWO)
• Principal Investigator: Carlos Frederico Martins Menck
• Grantee: Mariana Centrone Zylberman
• Host Institution: Instituto de Ciências Biomédicas (ICB). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated research grant: 19/19435-3 - The role of DNA damage and mitochondrial function in vascular, immune and neurological ageing (DNA MoVINg), AP.TEM

Abstract

There are many environmental DNA damaging agents, one of the most relevant being ultraviolet (UV) radiation, a component of sunlight. The main types of lesions formed by UV exposure are the cyclobutane pyrimidine dimers (CPDs) and 6-4 pyrimidine pyrimidone (6-4PPs) that, in most organisms, are efficiently repaired by specific photolyases for each type of lesion. However, such enzymes cannot be found in placental mammals, so that they employ the nucleotide excision repair (NER) pathway for removing such photoproducts from the DNA molecule. In a NER sub-pathway, global genome repair (GGR), the lesions are recognized by the XPC protein, who promotes the recruitment of other NER proteins. Mutations in this protein are responsible for deficient GGR and clinical manifestation of Xeroderma Pigmentosum, a disease characterized by a higher frequency of lesions, including cancer, in skin exposed to sunlight. Therefore, the premise of this project is the development of a strategy for CPD and 6-4PP photolyases in cells derived from an XP-C patient through transfection with messenger RNAs (mRNAs) that codify such proteins. The action of these enzymes in specific photoremotion of CPDs or 6-4PPs will allow the investigation of each lesion's role in the mutagenesis process in the absence of repair. (AU)