Role of Homodimerization of Human Cytomegalovirus DNA Polymerase Accessory Protein UL44 in Origin-Dependent DNA Replication in Cells

@article{Sinigalia2008RoleOH,
  title={Role of Homodimerization of Human Cytomegalovirus DNA Polymerase Accessory Protein UL44 in Origin-Dependent DNA Replication in Cells},
  author={Elisa Sinigalia and Gualtiero Alvisi and Beatrice Mercorelli and Donald M Coen and Gregory S. Pari and David Andrew Jans and Alessandro Ripalti and Giorgio Pal{\`u} and Arianna Loregian},
  journal={Journal of Virology},
  year={2008},
  volume={82},
  pages={12574 - 12579}
}
ABSTRACT The presumed processivity subunit of human cytomegalovirus (HCMV) DNA polymerase, UL44, forms homodimers. The dimerization of UL44 is important for binding to DNA in vitro; however, whether it is also important for DNA replication in a cellular context is unknown. Here we show that UL44 point mutants that are impaired for dimerization, but not for nuclear localization or interaction with the C terminus of the polymerase catalytic subunit, are not capable of supporting HCMV oriLyt… 

The Carboxy-Terminal Segment of the Human Cytomegalovirus DNA Polymerase Accessory Subunit UL44 Is Crucial for Viral Replication

Although the amino-terminal domain was sufficient for origin-dependent synthesis in a transient-transfection assay, the carboxy- terminal segment was crucial for virus replication and for the formation of DNA replication compartments in infected cells, even when this segment was replaced with a simian virus 40 NLS that ensured nuclear localization.

The Human Cytomegalovirus DNA Polymerase Processivity Factor UL44 Is Modified by SUMO in a DNA-Dependent Manner

It is shown that overexpression of SUMO alters the intranuclear distribution of UL44 in HCMV-infected cells, and enhances both virus production and DNA replication, arguing for an important role for sumoylation in H CMV life cycle and UL44 function(s).

Analysis of the Association of the Human Cytomegalovirus DNA Polymerase Subunit UL44 with the Viral DNA Replication Factor UL84

Results strongly suggest that UL44 and UL84 interact directly using a region of UL44 different from the UL54 binding site, which means UL44 can bind interacting replication proteins using a mechanism different from that of PCNA.

The Flexible Loop of the Human Cytomegalovirus DNA Polymerase Processivity Factor ppUL44 Is Required for Efficient DNA Binding and Replication in Cells

ULTS indicate that ppUL44Δloop is functional in dimerization and binding to pUL54 but strongly impaired in binding nuclear structures within the nucleus, as shown by its inability to form nuclear speckles, reduced nuclear accumulation, and increased intranuclear mobility compared to wild-type pUL44.

Live-Cell Analysis of Human Cytomegalovirus DNA Polymerase Holoenzyme Assembly by Resonance Energy Transfer Methods

Intriguingly, substitutions preventing DNA binding of ppUL44 influence the BRETmax of protein–protein interactions, implying that binding to dsDNA induces conformational changes both in the ppul44 homodimer and in the DNA polymerase holoenzyme.

Towards the identification of small molecules inhibiting he dimerization of HCMV DNA polymerase processivity factor UL44

It is confirmed that UL44 forms dimers in cells, as well as gaining insights relative to the formation of HMCV DNA polymerase holoenzyme, suggesting conformational changes within UL44 upon DNA binding in complex to UL54.

Regulated Transport into the Nucleus of Herpesviridae DNA Replication Core Proteins

Mechanisms controlling the nuclear import of herpesviral DNA replication machinery are summarized and potential implications for the development of antiviral compounds aimed at inhibiting the Herpesvirus life cycle are discussed.

Divide et Impera: Identification of Small-Molecule Inhibitors of HCMV Replication Interfering with Dimerization of DNA Polymerase Processivity Factor UL44

It is shown that full length UL44 dimerizes in a cellular context with high affinity and that such interaction could be targeted by small molecules, thus inhibiting the replication of several HCMV strains, including a drug-resistant mutant.

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