Nucleic acid binding properties of SmZF1, a zinc finger protein of Schistosoma mansoni.
During its life cycle, the flat worm Schistosoma mansoni is exposed to diverse environmental conditions and changes its morphological form. Each change calls for distinct patterns of gene expression. In order to understand the regulation of gene expression, it is necessary to identify regulatory elements in the promoter region of genes, and DNA transacting factors that control transcription. Zinc finger protein domains are responsible for transcription regulation of diverse genes in a wide range of organisms and are also involved in the promotion of protein-protein interactions. A transcript homologous to zinc finger gene sequences was isolated from a S. mansoni adult worm cDNA library and named SmZF1. It codes for a protein of 164 amino acids presenting three C(2)H(2) type zinc finger motifs. The recombinant SmZF1 protein was expressed and used on electrophoretic mobility shift assays to investigate the binding specificity of SmZF1 for DNA and RNA oligonucleotides. Our results demonstrated that SmZF1 binds both ds and ss DNA oligonucleotides, with an apparent preference for the specific D1-3DNA oligonucleotide, and also binds RNA oligonucleotides with lower affinity. Although we found that SmZF1 recognises DNA and RNA oligonucleotides not containing putative target sites, SmZF1 binds preferentially to sequence specific sites. Furthermore, unrelated oligonucleotides are not able to abolish this interaction. In silico studies identified putative SmZF1 binding sites in the complete genome of three model organisms and in partial genome sequences of S. mansoni. Six Drosophila genes presented these binding sites in their promoter region, indicating that they might be controlled by transcription factors containing zinc fingers motifs. Taken together, these results suggest that SmZF1 acts as a putative transcription factor of S. mansoni.
Calzavara-Silva
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Departamento de Bioquímica e Imunologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais-UFMG, Avenida Antônio Carlos 6627, Belo Horizonte, MG 31270-010, Brazil.
Prosdocimi
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Abath
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Pena
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Franco
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D000818:Animals; D001483:Base Sequence; D018509:DNA, Helminth / Q000235:genetics; D004268:DNA-Binding Proteins / Q000235:genetics; D024202:Electrophoretic Mobility Shift Assay / Q000379:methods; D005786:Gene Expression Regulation / Q000235:genetics; D015801:Helminth Proteins / Q000235:genetics*; D009696:Nucleic Acids / Q000235:genetics*; D009841:Oligonucleotides / Q000235:genetics; D011401:Promoter Regions, Genetic / Q000235:genetics; D018510:RNA, Helminth / Q000235:genetics; D016601:RNA-Binding Proteins / Q000235:genetics; D011994:Recombinant Proteins / Q000235:genetics; D012550:Schistosoma mansoni / Q000235:genetics*; D014157:Transcription Factors / Q000235:genetics*; D016335:Zinc Fingers / Q000235:genetics*
D018509:DNA, Helminth; D004268:DNA-Binding Proteins; D015801:Helminth Proteins; D009696:Nucleic Acids; D009841:Oligonucleotides; D018510:RNA, Helminth; D016601:RNA-Binding Proteins; D011994:Recombinant Proteins; C440069:SmZF1 protein, Schistosoma mansoni; D014157:Transcription Factors