Authors:

Sungyu Choi

Date Created:

Not specified

Course Title:

Professor:

Not specified

About Paper:

High-risk strains of human papillomavirus (HPV), notably HPV 16 and HPV 18, are leading causes of invasive cervical cancer (71.2%) and can also cause oropharyngeal, anal, head, and neck cancers. Modern research focuses on hindering HPV 16/18-related tumorigenesis by targeting the highly conserved E7 and E6 oncoproteins. This study emphasizes the E6 oncoprotein, which degrades the tumor suppressor protein p53 by forming a complex with E6AP (ubiquitin protein ligase E3A, UBE3A) via an E6AP LxxLL motif, leading to p53 ubiquitination, degradation, and uncontrolled cell proliferation. Peptides containing the E6AP LxxLL motif alone are sufficient for inducing p53 binding to E6. X-ray diffraction and cryogenic electron microscopy (cryo-EM) structures of this p53 degradation complex suggest interactions between the E6 N-terminus and p53. Simulations have revealed that the E6 N-terminus transitions from a folded, non-accessible state to an unstructured, solvent-exposed state when E6 binds to LxxLL peptides. Based on these results, it is hypothesized that this "unsheathed" N-terminal domain acts as a hook to latch onto p53 for recruitment. To test this hypothesis, various lengths of the E6 N-terminal residues were synthesized using solid-phase synthesis, purified, and labeled with dye for fluorescence polarization (FP) assays to analyze their interaction with p53. Binding affinities, represented by equilibrium dissociation constants from FP assays, will be identified for this potential interaction site within the E6-p53 complex. Successful FP data analysis would provide valuable insights into inhibiting HPV-induced cancers by targeting the E6-p53 interaction, offering a promising avenue for drug development and screening methods. Keywords: E6 N-Terminal; p53; HPV; Fluorescence Polarization; Peptide Synthesis

Source:

Purdue University / 2024

Topics:

No topics listed

Co-authors:

Sungyu Choi