Related Experiment Video
Updated: Jul 7, 2026
13:22
Genetic Screen for Identification of Multicopy Suppressors in Schizosaccharomyces pombe
Published on: September 13, 2022
Two conserved modules of Schizosaccharomyces pombe Mediator regulate distinct cellular pathways
Tomas Linder1, Nina N Rasmussen, Camilla O Samuelsen
1Division of Metabolic Diseases, Karolinska Institutet, Novum, SE-141 86 Stockholm, Sweden. tlinder@cmp.ucsf.edu
Nucleic Acids Research
|March 4, 2008
Summary
The Schizosaccharomyces pombe Mediator complex has distinct head and Cdk8 modules. Functional analysis reveals these modules control different cellular processes, including cell adhesion and separation, with conserved functions across yeast species.
Area of Science:
- Molecular Biology
- Genetics
- Biochemistry
Background:
- The Mediator complex is essential for RNA polymerase II transcription across eukaryotes.
- In Schizosaccharomyces pombe, Mediator comprises a core complex (head and middle domains) and a Cdk8 regulatory subcomplex.
- Understanding Mediator's functional modularity is key to deciphering gene regulation.
Purpose of the Study:
- To functionally characterize the Schizosaccharomyces pombe Mediator complex.
- To elucidate the molecular architecture and functional roles of Mediator submodules.
- To compare Mediator function between Schizosaccharomyces pombe and Saccharomyces cerevisiae.
Main Methods:
- Isolation and biochemical analysis of temperature-sensitive (ts) and deletion (Deltamed) alleles of Mediator subunits.
- Phenotypic analysis of Mediator mutants, including cell flocculation and hyphal growth.
- Gene expression profiling of Mediator mutants.
Main Results:
- Identified S. pombe Med20 head subunit and isolated ts alleles of med17+.
- Biochemical analysis revealed a stepwise molecular architecture of the Mediator head domain.
- Mediator mutants were classified into two groups: Cdk8 module mutants (flocculation) and head module mutants (hyphal growth due to defective cell separation regulated by Ace2).
Conclusions:
- The Schizosaccharomyces pombe Mediator exhibits functional modularity, with distinct roles for the Cdk8 and head modules.
- Head module function is critical for cell separation, while Cdk8 module affects cell adhesion.
- These functionally distinct modules and their conserved roles are conserved between S. pombe and S. cerevisiae.
Related Concept Videos
01:19Interactions Between Signaling Pathways
Signaling cascades usually lack linearity. Multiple pathways interact and regulate one another, allowing cells to integrate and respond to diverse environmental stimuli.
Convergence and divergence, and cross-talk between signaling pathways
Two distinct signaling pathways can converge on a single functional unit, which may either be a single protein or a complex of proteins. The response is either functionally distinct or synergistic between the two pathways but different from the response...
Convergence and divergence, and cross-talk between signaling pathways
Two distinct signaling pathways can converge on a single functional unit, which may either be a single protein or a complex of proteins. The response is either functionally distinct or synergistic between the two pathways but different from the response...
01:28Yeast Signaling
Yeasts are single-celled organisms, but unlike bacteria, they are eukaryotes (cells with a nucleus). Cell signaling in yeast is similar to signaling in other eukaryotic cells. A ligand, such as a protein or a small molecule released from a yeast cell, attaches to a receptor on the cell surface. The binding stimulates second-messenger kinases to activate or inactivate transcription factors that further regulate gene expression. Many of the yeast intracellular signaling cascades have similar...
02:17Separation of Sister Chromatids
At the transition from prophase to metaphase, there is a reduction in cohesion along the chromosomal arms, resulting in the resolution of sister chromatids. However, residual cohesin connections remain to hold the sister chromatids together until the transition from metaphase to anaphase. The residual connection prevents any premature separation of sister chromatids, blocking the risks of aneuploidy within the daughter cells.
At the onset of anaphase, separase, a proteolytic enzyme, is...
At the onset of anaphase, separase, a proteolytic enzyme, is...
01:42Microtubule Associated Proteins (MAPs)
Microtubule function and architecture are regulated by an array of specialized proteins called microtubule-associated proteins or MAPs. These proteins are widespread across different organisms and have conserved protein motifs, like the multi-TOG domain for tubulin binding found in the CLASP family of MAPs. Some MAPs are lineage-specific based on their conserved domains. Their functions depend upon the cytoskeletal architecture and cell type they are located within. In-plant cells, a specific...
01:25cAMP-dependent Protein Kinase Pathways
Cyclic Adenosine Monophosphate (cAMP) is an essential second messenger that activates protein kinase A (PKA) and regulates various biological processes. A single epinephrine molecule binds to GPCR and activates several heterotrimeric G proteins, each stimulating multiple adenylyl cyclase, amplifying the signal, and synthesizing large numbers of cAMP molecules. Small changes in cAMP concentration affect PKA activity. The binding of four cAMP molecules induces a conformational change in PKA,...
01:57Protein Complexes with Interchangeable Parts
Groups of proteins may form a complex where each protein in this complex has a different role in the overall execution of the complex’s function. Often some of the proteins in the complex can be replaced by a closely related variant to give a complex that contains many of the same components yet is functionally distinct.
The SCF ubiquitin ligase is a protein complex of five individual proteins. This complex attaches ubiquitin to other target proteins to mark them for degradation. In order to...
The SCF ubiquitin ligase is a protein complex of five individual proteins. This complex attaches ubiquitin to other target proteins to mark them for degradation. In order to...