title: A novel role for RAD54: this host protein modulates geminiviral DNA replication.
abstract: Geminiviruses primarily encode only few factors, such as replication initiator protein (Rep), and need various host cellular machineries for rolling-circle replication (RCR) and/or recombination-dependent replication (RDR). We have identified a host factor, RAD54, in a screen for Rep-interacting partners and observed its role in DNA replication of the geminivirus mungbean yellow mosaic India virus (MYMIV). We identified the interacting domains ScRAD54 and MYMIV-Rep and observed that ScRAD54 enhanced MYMIV-Rep nicking, ATPase, and helicase activities. An in vitro replication assay demonstrated that the geminiviral DNA replication reaction depends on the viral Rep protein, viral origin of replication sequences, and host cell-cycle proteins. Rad54-deficient yeast nuclear extract did not support in vitro viral DNA replication, while exogenous addition of the purified ScRAD54 protein enhanced replication. The role of RAD54 in in planta replication was confirmed by the transient replication assay; i.e., agroinoculation studies. RAD54 is a well-known recombination/repair protein that uses its DNA-dependent ATPase activity in conjunction with several other host factors. However, this study demonstrates for the first time that the eukaryotic rolling-circle replicon depends on the RAD54 protein.
authors.affiliation: Plant Molecular Biology Group, International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi-110 067, India.
authors.forename: Kosalai
authors.initials: K
authors.lastname: Kaliappan
authors.forename: Nirupam Roy
authors.initials: NR
authors.lastname: Choudhury
authors.forename: Geetika
authors.initials: G
authors.lastname: Suyal
authors.forename: Sunil Kumar
authors.initials: SK
authors.lastname: Mukherjee
mesh_terms: D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism / Q000821:virology; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism; D001483:Base Sequence; D053839:Begomovirus / Q000235:genetics / Q000378:metabolism* / Q000502:physiology; D004265:DNA Helicases / Q000235:genetics / Q000378:metabolism*; D045643:DNA Repair Enzymes / Q000235:genetics / Q000378:metabolism; D004261:DNA Replication; D004279:DNA, Viral / Q000235:genetics / Q000378:metabolism / Q000648:ultrastructure; D054884:Host-Pathogen Interactions; D008854:Microscopy, Electron; D008969:Molecular Sequence Data; D019151:Peptide Library; D011485:Protein Binding; D054730:Protein Interaction Domains and Motifs / Q000235:genetics; D025941:Protein Interaction Mapping; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism / Q000821:virology; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D017361:Viral Nonstructural Proteins / Q000235:genetics / Q000378:metabolism*; D014764:Viral Proteins / Q000235:genetics / Q000378:metabolism*; D014779:Virus Replication
chemical_list: D029681:Arabidopsis Proteins; D004279:DNA, Viral; D019151:Peptide Library; C518800:RAD54 protein, Arabidopsis; D029701:Saccharomyces cerevisiae Proteins; D017361:Viral Nonstructural Proteins; D014764:Viral Proteins; C075468:RAD54 protein, S cerevisiae; D004265:DNA Helicases; D045643:DNA Repair Enzymes