Related Experiment Videos
The Schizosaccharomyces pombe mei4+ gene encodes a meiosis-specific transcription factor containing a forkhead
S Horie1, Y Watanabe, K Tanaka
1Department of Biology, Faculty of Science, Osaka City University, Osaka, Japan.
Abstract:
The mei4+ gene of the fission yeast Schizosaccharomyces pombe was cloned by functional complementation. The mei4 disruptant failed to complete meiosis-I but could proliferate normally. mei4+ was transcribed only in meiosis-proficient diploid cells after premeiotic DNA replication. The mei4+ open reading frame encodes a 57-kDa serine-rich protein comprised of 517 amino acids with a forkhead/HNF3 DNA-binding domain in the amino-terminal region. Transcription of spo6+, a gene required for sporulation, was dependent on the mei4+ function. Two copies of the GTAAAYA consensus sequence, proposed as the binding site for human forkhead proteins, were found in the promoter region of spo6+. A gel mobility shift assay demonstrated the sequence-dependent binding of the GST-Mei4 forkhead domain fusion protein to DNA fragments with one of the consensus elements. Deletion of this consensus element from the spo6 promoter abolished the transcription of spo6+ and resulted in a sporulation deficiency. One-hybrid assay of Mei4 which was fused to the Gal4 DNA-binding domain localized the transcriptional activation domain in the C-terminal 140 amino acids of Mei4. These results indicate that Mei4 functions as a meiosis-specific transcription factor of S. pombe.
Insights
The mei4+ gene in fission yeast is crucial for completing meiosis. Mei4 acts as a meiosis-specific transcription factor, regulating genes essential for sporulation and successful cell division.
Area of Science:
- Molecular Biology
- Genetics
- Cell Biology
Background:
- The mei4+ gene in Schizosaccharomyces pombe is essential for meiosis.
- Understanding the function of mei4+ is key to deciphering the mechanisms of meiotic progression and sporulation.
Purpose of the Study:
- To clone and characterize the mei4+ gene.
- To determine the role of Mei4 in meiosis and sporulation in S. pombe.
- To identify the DNA-binding and transcriptional activation domains of Mei4.
Main Methods:
- Functional complementation for gene cloning.
- Northern blot analysis for gene transcription.
- Sequence analysis of the mei4+ open reading frame.
- Gel mobility shift assay and one-hybrid assay for protein-DNA interactions and transcriptional activation.
Main Results:
- The mei4+ gene product is a 57-kDa protein with a forkhead/HNF3 DNA-binding domain.
- Mei4+ is transcribed only in meiosis-proficient diploid cells post-DNA replication.
- Mei4+ is required for the transcription of spo6+, a gene essential for sporulation.
- Mei4+ directly binds to consensus sequences in the spo6+ promoter and functions as a transcription factor.
Conclusions:
- Mei4 functions as a meiosis-specific transcription factor in S. pombe.
- Mei4 regulates the transcription of sporulation genes like spo6+.
- The forkhead DNA-binding domain and C-terminal activation domain are critical for Mei4 function.