KSHV encoded LANA recruits Nucleosome Assembly Protein NAP1L1 for regulating viral DNA replication and transcription

Sci Rep. 2016 Sep 7;6:32633. doi: 10.1038/srep32633.

Abstract

The establishment of latency is an essential for lifelong persistence and pathogenesis of Kaposi's sarcoma-associated herpesvirus (KSHV). Latency-associated nuclear antigen (LANA) is the most abundantly expressed protein during latency and is important for viral genome replication and transcription. Replication-coupled nucleosome assembly is a major step in packaging the newly synthesized DNA into chromatin, but the mechanism of KSHV genome chromatinization post-replication is not understood. Here, we show that nucleosome assembly protein 1-like protein 1 (NAP1L1) associates with LANA. Our binding assays revealed an association of LANA with NAP1L1 in KSHV-infected cells, which binds through its amino terminal domain. Association of these proteins confirmed their localization in specific nuclear compartments of the infected cells. Chromatin immunoprecipitation assays from NAP1L1-depleted cells showed LANA-mediated recruitment of NAP1L1 at the terminal repeat (TR) region of the viral genome. Presence of NAP1L1 stimulated LANA-mediated DNA replication and persistence of a TR-containing plasmid. Depletion of NAP1L1 led to a reduced nucleosome positioning on the viral genome. Furthermore, depletion of NAP1L1 increased the transcription of viral lytic genes and overexpression decreased the promoter activities of LANA-regulated genes. These results confirmed that LANA recruitment of NAP1L1 helps in assembling nucleosome for the chromatinization of newly synthesized viral DNA.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antigens, Viral / chemistry
  • Antigens, Viral / metabolism*
  • Cell Line, Tumor
  • DNA Replication*
  • DNA, Viral / metabolism
  • Electrophoresis, Gel, Two-Dimensional
  • Gene Expression Regulation, Viral
  • Genome, Viral
  • HEK293 Cells
  • Herpesvirus 8, Human / genetics
  • Herpesvirus 8, Human / metabolism*
  • Humans
  • Immunoprecipitation
  • Nuclear Proteins / chemistry
  • Nuclear Proteins / metabolism*
  • Nucleosome Assembly Protein 1 / chemistry
  • Nucleosome Assembly Protein 1 / metabolism*
  • Nucleosomes / metabolism*
  • Plasmids / metabolism
  • Promoter Regions, Genetic / genetics
  • Protein Binding
  • Protein Domains
  • Proteomics
  • RNA, Messenger / genetics
  • RNA, Messenger / metabolism
  • Transcription, Genetic*
  • Up-Regulation / genetics
  • Virus Replication*

Substances

  • Antigens, Viral
  • DNA, Viral
  • NAP1L1 protein, human
  • Nuclear Proteins
  • Nucleosome Assembly Protein 1
  • Nucleosomes
  • RNA, Messenger
  • latency-associated nuclear antigen