Disease relevance of Rep

• We analyzed circovirus and nanovirus replication initiator protein (Rep) sequences and confirmed that an N-terminal region in circovirus Reps is similar to an equivalent region in nanovirus Reps [1].
• However, we found that the remaining C-terminal region is related to an RNA-binding protein (protein 2C), encoded by picorna-like viruses, and we concluded that the sequence encoding this region of Rep was acquired from one of these single-stranded RNA viruses, probably a calicivirus, by recombination [1].
• The "RecRep2 family" comprised some previously identified Rep-like genes from plasmids of phytoplasmas and similar Rep-like genes from the genomes of Lactobacillus acidophilus, Lactococcus lactis, and Phytoplasma asteris [2].
• The Rep genes of circoviruses were the best characterized members of the "RecRep1 family." Other members of the RecRep1 family were Rep-like genes found in the genomes of the Canarypox virus, Entamoeba histolytica, and Giardia duodenalis and in a plasmid, p4M, from the Gram-positive bacterium, Bifidobacterium pseudocatenulatum [2].
• This region of protein identity corresponds with the putative plant circovirus replication-associated protein (Rep) [3].

High impact information on Rep

• The nanovirus Banana bunchy top virus (BBTV) has six standard components in its genome and occasionally contains components encoding additional Rep (replication initiation protein) genes [4].
• We speculate that RecRep genes have been transferred from viruses or plasmids to parasitic protozoan and bacterial genomes and that Rep proteins were themselves involved in the original recombination events that generated the ancestral RecRep genes [2].
• A low level of activity was found for the promoters of C11, which encodes a master replication-initiator protein (Rep), and C1, C2, C3 and C10, which encode additional Reps, in both transgenic tobacco calli and plants [5].
• It was shown that CFDV Rep associated predominantly with nuclei and membranes of infected/transfected cells [6].
• Similar to C1 and C2, two of the new components (C7 and C9) encode putative replication-associated (Rep) proteins of 33.2 and 32.7 kDa, respectively, the former of which is 90% identical to the C10 Rep protein of milk vetch dwarf virus (MDV) [7].

Biological context of Rep

• The phylogeny of replication (Rep) proteins indicate that this small viral multi-gene family has evolved by a process of duplication and subsequent loss of Rep-encoding genome components, analogous to the "birth-and-death" process of evolution which has been described in eukaryotic multi-gene families [8].

Associations of Rep with chemical compounds

• All ten components of the FBNYV genome, except the Rep components C2 and C9, had closely related counterparts in the MDV genome [7].

Analytical, diagnostic and therapeutic context of Rep

• Subcellular distribution of the CFDV Rep was studied by fractionation of insect cells infected with recombinant baculovirus expressing the 6x His-Rep protein and by laser scanning confocal microscopy of Nicotiana benthamiana epidermal cells bombarded with a construct encoding CFDV Rep fused to GFP [6].

References