Aislamiento e identificación de proteínas de unión a una secuencia específica del promotor del gen calmodulina de Plasmodium falciparum
2003; National University of Colombia; Volume: 5; Issue: 1 Linguagem: Inglês
ISSN
0123-3475
AutoresErika Yara, Jacqueline Chaparro‐Olaya,
Tópico(s)Invertebrate Immune Response Mechanisms
ResumoThis study continues the search for Plasmodium falciparum transcriptional machinery by isolating DNA binding proteins that could contribute towards discovering new therapeutic targets. The calmodulin gene was thus used as the model, using a 149 bp DNA fragment (PAE’CAM149) specific for the 5' non-translated region. Partially purified proteins derived from total parasite nuclear extract were used to scale the PAE’CAM149-biotina-streptavidin-magnesphere DNA affinity microsystem previously developed for capturing those proteins specifically binding to the DNA PAE’CAM149 sequence. The scaling allowed the protein to be recycled three times through chromatographic matrix and determine which proteins remained bound to the system, indicating specific interaction with the calmodulin gene (PAE’CAM149) promoter sequence. It also enabled obtaining the quantity of protein necessary for sequencing. Other assays allowed binding activity to be tracked by using eukaryotic transcription factor consensus sequences (CREB, OCT1, MIG, GATA), leading to selecting a 54 kDa protein whose possible identity corresponds to the E4BP4 transcription factor or related sequences. Problems regarding quantity were overcome in this work. Binding specificity was ascertained and it was determined that the 54 kDa protein had an intrinsic modification impeding its amino terminal being sequenced. These assays showed that CREB, or related transcription factors, form part of the parasite's transcriptional machinery. Key words: malaria; Plasmodium falciparum; machinery; transcription; transcription factors
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