Identificação de um fator do hospedeiro, RPS5A, envolvido na interação com a proteína de movimento (MP) de geminivírus

• Autor(a) principal: Balmant, Kelly Mayrink
• Data de Publicação: 2011
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/4743
• topic: Geminivírus; Interação protéica; Proteína de movimento; Proteína ribossomal S5A; Geminivirus; Protein interaction; Movement protein; Ribosomal protein S5A; CNPQ::CIENCIAS BIOLOGICAS::GENETICA::GENETICA MOLECULAR E DE MICROORGANISMOS

The movement protein MP from bipartite geminivirus (begomovirus) facilitates the cell-to-cell and long-distance transport of viral DNA in addition to affecting viral pathogenicity. To identify host factors that interact with MP, initially a cDNA library prepared from CaLCuV (Cabbage leaf curl virus)-infected Arabidopsis leaf mRNA was generated in a pEXPAD502 vector. To select for interactions between the bait BD-MP and cDNA library-encoded proteins, double transformants (BD-MP+ cDNA-AD) were plated on medium lacking histidine but supplemented with 3-aminotriazole (3-AT). From 5 x 105 transformants screened, two clones, encoding AtEXL3 (Exordium Like 3), a cell wall protein, and AtRPS5A, ribosomal protein S5A, displayed histidine/adenine auxotrophy and activate LacZ expression, on X-gal indicator plates. Expression of a full-length RPS5A cDNA fused to the Gal4 activation domain in yeast carrying BD-MP promoted growth of the double transformants in the absence of histidine and presence of 3-AT, in addition to activating high levels of LacZ expression. Furthermore, the interaction between MP and RPS5A was confirmed in vitro by pull down assays. Analysis of RPS5A gene expression by qRT-PCR demonstrated that the accumulation of rpS5A transcripts is suppressed by geminivirus infection. Based on these results and others, a functional model for the MP-RPS5A interaction is discussed.