title: Interaction between TATA-Binding Protein (TBP) and Multiprotein Bridging Factor-1 (MBF1) from the Filamentous Insect Pathogenic Fungus Beauveria bassiana.
abstract: TATA-binding protein (TBP) is a ubiquitous component of eukaryotic transcription factors that acts to nucleate assembly and position pre-initiation complexes. Multiprotein bridging factor 1 (MBF1) is thought to interconnect TBP with gene specific transcriptional activators, modulating transcriptional networks in response to specific signal and developmental programs. The insect pathogen, Beauveria bassiana, is a cosmopolitan fungus found in most ecosystems where it acts as an important regulator of insect populations and can form intimate associations with certain plants. In order to gain a better understanding of the function of MBF1 in filamentous fungi, its interaction with TBP was demonstrated. The MBF1 and TBP homologs in B. bassiana were cloned and purified from a heterologous E. coli expression system. Whereas purified BbTBP was shown to be able to bind oligonucleotide sequences containing the TATA-motif (Kd ≈ 1.3 nM) including sequences derived from the promoters of the B. bassiana chitinase and protease genes. In contrast, BbMBF1 was unable to bind to these same target sequences. However, the formation of a ternary complex between BbMBF1, BbTBP, and a TATA-containing target DNA sequence was seen in agarose gel electrophoretic mobility shift assays (EMSA). These data indicate that BbMBF1 forms direct interactions with BbTBP, and that the complex is capable of binding to DNA sequences containing TATA-motifs, confirming that BbTBP can link BbMBF1 to target sequences as part of the RNA transcriptional machinery in fungi.
authors.affiliation: Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences; Key Laboratory of Microbial Resources, Ministry of Agriculture, Beijing 100081, China; Department of Microbiology and Cell Science, Institute of Food and Agricultural Science, University of Florida, Bldg 981, Museum Rd., Gainesville, FL 32611, United States of America.
authors.forename: Chi
authors.initials: C
authors.lastname: Song
authors.affiliation: Department of Microbiology and Cell Science, Institute of Food and Agricultural Science, University of Florida, Bldg 981, Museum Rd., Gainesville, FL 32611, United States of America.
authors.forename: Almudena
authors.initials: A
authors.lastname: Ortiz-Urquiza
authors.affiliation: Institute of Microbiology, College of Life Sciences, Zhejiang University, Hangzhou 310058, China.
authors.forename: Sheng-Hua
authors.initials: SH
authors.lastname: Ying
authors.affiliation: Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences; Key Laboratory of Microbial Resources, Ministry of Agriculture, Beijing 100081, China.
authors.forename: Jin-Xia
authors.initials: JX
authors.lastname: Zhang
authors.affiliation: Department of Microbiology and Cell Science, Institute of Food and Agricultural Science, University of Florida, Bldg 981, Museum Rd., Gainesville, FL 32611, United States of America.
authors.forename: Nemat O
authors.initials: NO
authors.lastname: Keyhani
mesh_terms: D000818:Animals; D052982:Beauveria / Q000235:genetics / Q000378:metabolism*; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism*; D015870:Gene Expression; D007313:Insecta / Q000382:microbiology; D011485:Protein Binding; D011994:Recombinant Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D035181:TATA-Box Binding Protein / Q000235:genetics / Q000378:metabolism*; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*
chemical_list: D005656:Fungal Proteins; D011994:Recombinant Proteins; D035181:TATA-Box Binding Protein; D014157:Transcription Factors