Truncated, strong inducible promoter Pmcl1 from Metarhizium anisopliae
In this study, Metarhizium collagen -like protein (MCL1) promoter from Metarhizium anisopliae was analysed and truncated into different sizes through series of targeted and random deletions based on the presence of various transcription factor-binding sites. Synthetic Green Fluorescent Protein (sGFP) was being utilized as a reporter gene to study the relative expression driving capability of unmodified and truncated promoters. Conserved promoter sequence analysis revealed similarity between the paralogous promoters from M. brunneum and M. acridum. sGFP expression in the haemolymph was directed with the help of mcl1 signal peptide sequence. Deleting the promoter region from − 2764 to − 1583 bp increases the promoter mcl1 (Pmcl1) activity by twofolds, while deletions of the regions upstream of − 1150 bp and − 840 bp caused a decrease of sGFP expression level (80% and 70%, respectively). Transcriptional binding sites predicted for the deleted region revealed the loss of upstream repressing sequences such as Matalpha2 along with ROX1 and Rap1 repressor-binding sites located − 2234 bp, − 1754 bp and − 1724 bp from the TSS. Compared with Pmcl1-wild type (2.7 kbp), Pmcl1-1583 bp had a shorter sequence and showed statistically significant expression in M. anisopliae. This study introduces a highly efficient strong inducible promoter for over-expression of target genes in M. anisopliae.
KeywordsMcl1 promoter Metarhizium collagen-like protein Promoter truncation Gene expression Entomopathogenic fungi
One of the authors, Kawkab Kanjo is thankful to Indian Council for Cultural relations, Government of India for providing fellowship (Code A-1206). The other authors highly acknowledge Ministry of Human Resource Development for the financial support in the form of research fellowship. The authors also acknowledge Department of Biosciences & Bioengineering and Central Instrumentation Facility of Indian Institute of Technology Guwahati for providing Instrumentation facility.
Compliance with ethical standards
Conflict of interest
The authors declare that there is no conflict of interest.
- Prior C, Greathead DJ (1989) Biological control of locusts: the potential for the exploitation of pathogens. Plant Prot Bull FAO 37:37–48Google Scholar