ABSTRACT
Background: In Saccharomyces cerevisiae, Msn2, which acts as a key transcription factor downstream the MAPKHOG cascade pathway, also regulates the expression of genes related to stress responses. However, little is known about the regulation mechanisms of the transcription factor in Setosphaeria turcica. Results: In this study, a zinc finger DNA-binding protein, designated as StMSN2, was cloned from S. turcica. Sequencing results showed that StMSN2 had a 1752 bp open reading frame (ORF), which was interrupted by an intron (135 bp) and encoded a putative 538-amino acid protein. Phylogenetic analysis further revealed that StMsn2 was more closely related to Msn2 of Aspergillus parasiticus. StMSN2 was cloned into the pET-28a vector with His (Histidine) tags and induced with 1 mM IPTG (isopropyl-ß-D-thiogalactoside) at 37°C. The recombinant His-tagged StMsn2 was purified, and a band of size approximately 58.8 kDa was obtained. The high specificity of the polyclonal antibody Msn2-2 was detected with the StMsn2 protein from S. turcica and prokaryotic expression system, respectively. Conclusions: A new gene, named StMSN2, with 1617 bp ORF was cloned from S. turcica and characterized using bioinformatics methods. StMsn2 was expressed and purified in a prokaryotic system. A polyclonal antibody, named Msn2-2, against StMsn2 with high specificity was identified.
Subject(s)
Plant Diseases , Ascomycota/genetics , Ascomycota/pathogenicity , Transcription Factors/isolation & purification , Ascomycota/metabolism , Stress, Physiological , Transcription Factors/genetics , Transcription Factors/metabolism , Carrier Proteins , Gene Expression , Blotting, Western , Open Reading Frames , Zinc Fingers , Cloning, Molecular , Zea mays , Escherichia coli , Helminthosporium , EpitopesABSTRACT
STK1 is one important MAPK gene regulating the conidial development, osmotic stress and pathogenicity of Setosphaeria turcica. At first, the Pichia pastoris GS115 expression vector pPIC3.5K-EGFP containing enhanced green fluorescent protein gene (EGFP) was constructed, then STK1 gene was first amplified by PCR with the template of cDNA of S. turcica model isolate 01-23, and then cloned into the vector pPIC3.5K-EGFP with enhanced green fluorescent protein gene (EGFP) to construct the STK1-EGFP fusion gene expression vector pPIC3.5K-STK1-EGFP. The vector was transformed into the susceptible cells of Pichia pastoris GS115 by electric shock process, and the transformants were identified by MD medium screening and PCR determination. The STK1 gene and EGFP gene could be expressed effectively and stably in the transformants as detected by RT-PCR and fluorescence observation. In addition, we also found that the Kozak sequence before the start codon of STK1 gene could increase 4.8 folds expression level of STK1- EGFP fusion gene. The above research results laid a good foundation for subcellular localization and antibody preparation of STK1 protein.