Lysine methylation as a novel regulatory mechanism of HPV E2 function

The National Institute of Allergy and Infectious Diseases awarded Marian University Inc. $208,880 on May 6, 2026, under the Allergy and Infectious Diseases Research program (CFDA 93.855) to investigate lysine methylation as a regulatory mechanism of human papillomavirus E2 protein function.

The research addresses fundamental HPV biology, specifically how the viral E2 protein—essential for viral genome replication, transcriptional activation, and tethering to host mitotic chromosomes—is regulated through post-translational modifications. The project will identify lysine methyltransferases responsible for E2 methylation and determine their biological function. HPV infections with high-risk strains can lead to cervical, anogenital, and oropharyngeal cancers accounting for 5 percent of all cancers worldwide; currently no effective non-invasive treatments against high-risk HPV infections exist.

Work is performed in Indianapolis, Indiana. The period of performance runs from the award date through April 30, 2028.

Abstract

Human papillomaviruses (HPV) are double-stranded DNA viruses that infect cutaneous and mucosal epithelia. Infections with high-risk hpvs may lead to cervical, anogenital, and oropharyngeal cancers accounting for 5% of all cancers worldwide. Currently there are no effective non-invasive treatments against high-risk HPV infections. Because of that, IT is critical to study the fundamental biology of high-risk HPV and specifically its utilization of host cell factors to permit completion of its viral life cycle. The viral replicative program consists of three different stages: (1) initial replication after infection, (2) stable maintenance of viral genomes and (3) amplification of viral episomes. The PV activator E2 and E1 DNA helicase proteins are the first proteins to be expressed after infection and are essential for HPV replication. The viral E2 protein is necessary for replication of the viral genome, activation of the viral early promoter for transcription, and tethering of viral genomes to host mitotic chromosomes in basal cells during cellular replication and division. Our long-term goal is to elucidate host factors necessary for E1-E2 dependent HPV replication and E2-mediated transcription throughout the viral lifecycle. Protein lysine methylation is emerging as an important post-translational modification that regulates the activity of transcription factors and histones. We recently identified four lysine residues methylated within the HPV-31 E2 by mass spectrometry confirming that E2 is a methylated protein. We hypothesize that that lysine methylation is an important regulatory process during the viral lifecycle. The overall objectives in this application are to (i) identify the lysine methyl transferases responsible for E2 methylation and (II) determine their biological function. The proposed research is significant because IT will define the mechanisms tightly controlled by E2 methylation throughout the HPV lifecycle. Ultimately, such knowledge has the potential to target mechanisms of persistent HPV infections.