Identification and analysis of a retinoblastoma binding motif in the replication protein of a plant DNA virus: requirement for efficient viral DNA replication.

摘要: Geminiviruses are plant DNA viruses with small genomes whose replication, except for the viral replication protein (Rep), depends on host proteins and, in this respect, analogous to animal tumor viruses, e.g. SV40. The mechanism by which these create a cellular environment permissive involves binding of virally encoded oncoprotein, through its LXCXE motif, retinoblastoma (Rb). We have identified such motif Rep wheat dwarf geminivirus (WDV) and we show functional importance during replication. Using yeast two-hybrid system demonstrated that WDV forms stable complexes p130Rbr2, member Rb family proteins, single amino acid changes within abolish ability bind p130Rbr2. is conserved other members same subgroup. presence an intact required efficient cultured cells, strongly suggesting one functions may be linking between cycles. Our results point existence Rb-like protein(s) cells playing regulatory roles cell cycle.