Publication details

Structure-activity relationships in polymorphic G-quadruplex forming segment of c-MYC promoter

Authors

RYNEŠ Jan FESSL T. KRAFČÍKOVÁ Michaela TRANTÍREK Lukáš TRANTÍRKOVÁ Silvie

Year of publication 2017
Type Conference abstract
MU Faculty or unit

Central European Institute of Technology

Citation
Description One of the driving forces of malignant transformation is activation of a protooncogene that is converted into oncogene by a mutation, which changes the protein function or expression. Misregulation of the proto-oncogene c-Myc has been identified in many human cancers. Therefore, the detailed knowledge of c-Myc regulation is necessary to develop appropriate therapies. Expression of c-Myc is co-regulated by a G-quadruplex that can be formed from a G-rich motif Pu27 within the c-Myc promoter. Pu27 consists of five G-tracts separated by one A or T nucleotide. Formation of a Gquadruplex requires only four G-tracts. Hence, the Pu27 segment give rise to several distinct G-quadruplex conformations. It is not known, which particular G-quadruplex conformation bears the biological role. To address this point, we have prepared a set of Pu27 oligonucleotides with naturally occurring nucleotide substitutions in different G-tracts that limit the number of possible G-quadruplex conformations. Using single particle FRET, we have identified populations of the G-quadruplex topologies that the Pu27 variants form in vitro. By performing pull-downs from nuclear lysates, we have revealed proteins that bind to the particular Gquadruplexes. To test the function, Pu27 element in the human c-Myc promoter has been mutated and the activity examined in a luciferase reporter assay. Preliminary data from our experiments indicate that there are several structural topologies of Gquadruplex formed from Pu27 sequence, which are functionally equivalent
Related projects: