Kaposi's sarcoma-associated herpesvirus K8 protein interacts with hSNF5

J Gen Virol. 2003 Mar;84(Pt 3):665-676. doi: 10.1099/vir.0.18699-0.

Abstract

Kaposi's sarcoma-associated herpesvirus (KSHV) is a human gammaherpesvirus related to Epstein-Barr virus (EBV) and herpesvirus saimiri. KSHV open reading frame K8 encodes a basic region-leucine zipper protein of 237 aa that homodimerizes. K8 shows significant similarity to the EBV immediate-early protein Zta, a key regulator of EBV reactivation and replication. In this study, a carboxyl-terminal deletion mutant of K8, K8(1-115), that had strong transactivating properties was found. Screening using transcriptionally inactive K8(1-75) showed that K8 interacts and co-localizes with hSNF5, a cellular chromatin-remodelling factor, both in vivo and in vitro. This interaction requires aa 48-183 of hSNF5 and 1-75 of K8. In a yeast expression system, the ability of K8 and K8(1-115) to activate transcription requires the presence of SNF5, the yeast homologue of hSNF5. These data suggest a mechanism by which the SWI-SNF complex is recruited to specific genes. They also suggest that K8 functions as a transcriptional activator under specific conditions and that its transactivation activity requires its interaction with the cellular chromatin remodelling factor hSNF5.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Basic-Leucine Zipper Transcription Factors
  • Carrier Proteins / chemistry
  • Carrier Proteins / genetics
  • Carrier Proteins / metabolism*
  • Chromosomal Proteins, Non-Histone
  • DNA-Binding Proteins / chemistry
  • DNA-Binding Proteins / metabolism*
  • Gene Deletion
  • Gene Expression Regulation, Viral
  • Herpesvirus 8, Human / chemistry
  • Herpesvirus 8, Human / metabolism*
  • Humans
  • Leucine Zippers
  • Protein Binding
  • Repressor Proteins
  • SMARCB1 Protein
  • Trans-Activators
  • Transcription Factors
  • Transcription, Genetic
  • Two-Hybrid System Techniques
  • Viral Proteins / chemistry
  • Viral Proteins / genetics
  • Viral Proteins / metabolism*
  • Virus Activation
  • Virus Replication

Substances

  • Basic-Leucine Zipper Transcription Factors
  • Carrier Proteins
  • Chromosomal Proteins, Non-Histone
  • DNA-Binding Proteins
  • K8 protein, Human herpesvirus 8
  • Repressor Proteins
  • SMARCB1 Protein
  • SMARCB1 protein, human
  • Trans-Activators
  • Transcription Factors
  • Viral Proteins