Analysis of Schizosaccharomyces pombe Mediator reveals a set of essential subunits conserved between yeast and metazoan cells

With the identification of eight new polypeptides, we here complete the subunit characterization of the Schizosaccharomyces pombe RNA polymerase II holoenzyme. The complex contains homologs to all 10 essential gene products present in the Saccharomyces cerevisiae Mediator, but lacks clear homologs to any of the 10 S. cerevisiae components encoded by nonessential genes. S. pombe Mediator instead contains three unique components (Pmc2, -3, and -6), which lack homologs in other cell types. Presently, pmc2+ and pmc3+ have been shown to be nonessential genes. The data suggest that S. pombe and S. cerevisiae share an essential protein module, which associates with nonessential speciesspecific subunits. In support of this view, sequence analysis of the conserved yeast Mediator components Med4 and Med8 reveals sequence homology to the metazoan Mediator components Trap36 and Arc32. Therefore, 8 of 10 essential genes conserved between S. pombe and S. cerevisiae also have a metazoan homolog, indicating that an evolutionary conserved Mediator core is present in all eukaryotic cells. Our data suggest a closer functional relationship between yeast and metazoan Mediator than previously anticipated.

[1]  Y. Liu,et al.  Yeast Nuclear Extract Contains Two Major Forms of RNA Polymerase II Mediator Complexes* , 2001, The Journal of Biological Chemistry.

[2]  R. Kornberg,et al.  Structural organization of yeast and mammalian mediator complexes. , 2000, Proceedings of the National Academy of Sciences of the United States of America.

[3]  J. Park,et al.  In Vivo Requirement of Activator-Specific Binding Targets of Mediator , 2000, Molecular and Cellular Biology.

[4]  M. Boube,et al.  Drosophila homologs of transcriptional mediator complex subunits are required for adult cell and segment identity specification. , 2000, Genes & development.

[5]  R. Kornberg,et al.  Mediator-nucleosome interaction. , 2000, Molecular cell.

[6]  R. Roeder,et al.  Transcriptional regulation through Mediator-like coactivators in yeast and metazoan cells. , 2000, Trends in biochemical sciences.

[7]  J. Qin,et al.  The USA-derived transcriptional coactivator PC2 is a submodule of TRAP/SMCC and acts synergistically with other PCs. , 2000, Molecular cell.

[8]  R. Darnell,et al.  Involvement of the TRAP220 component of the TRAP/SMCC coactivator complex in embryonic development and thyroid hormone action. , 2000, Molecular cell.

[9]  C. Gustafsson,et al.  Purification and Characterization of RNA Polymerase II Holoenzyme from Schizosaccharomyces pombe * , 2000, The Journal of Biological Chemistry.

[10]  S. Han,et al.  Caenorhabditis elegans mediator complexes are required for developmental-specific transcriptional activation. , 1999, Proceedings of the National Academy of Sciences of the United States of America.

[11]  W. P. Wahls,et al.  High‐efficiency gene targeting in Schizosaccharomyces pombe using a modular, PCR‐based approach with long tracts of flanking homology , 1999, Yeast.

[12]  R. Young,et al.  Ubiquitous expression and embryonic requirement for RNA polymerase II coactivator subunit Srb7 in mice. , 1999, Genes & development.

[13]  S. Forsburg,et al.  The best yeast? , 1999, Trends in genetics : TIG.

[14]  R. Tjian,et al.  Purification of transcription cofactor complex CRSP. , 1999, Proceedings of the National Academy of Sciences of the United States of America.

[15]  E. Lees,et al.  Mammalian Srb/Mediator complex is targeted by adenovirus E1A protein , 1999, Nature.

[16]  R. Tjian,et al.  Composite co-activator ARC mediates chromatin-directed transcriptional activation , 1999, Nature.

[17]  Paul Tempst,et al.  Ligand-dependent transcription activation by nuclear receptors requires the DRIP complex , 1999, Nature.

[18]  R. Kornberg,et al.  Conserved structures of mediator and RNA polymerase II holoenzyme. , 1999, Science.

[19]  P. Brown,et al.  Mediator protein mutations that selectively abolish activated transcription. , 1999, Proceedings of the National Academy of Sciences of the United States of America.

[20]  D. Reinberg,et al.  NAT, a human complex containing Srb polypeptides that functions as a negative regulator of activated transcription. , 1998, Molecular cell.

[21]  R. Kornberg,et al.  Mammalian mediator of transcriptional regulation and its possible role as an end-point of signal transduction pathways. , 1998, Proceedings of the National Academy of Sciences of the United States of America.

[22]  K. Gevaert,et al.  A peptide concentration and purification method for protein characterization in the subpicomole range using matrix assisted laser desorption/ionization‐postsource decay (MALDI‐PSD) sequencing , 1998, Electrophoresis.

[23]  Young Chul Lee,et al.  A transcriptional mediator protein that is required for activation of many RNA polymerase II promoters and is conserved from yeast to humans , 1997, Molecular and cellular biology.

[24]  C. Chang,et al.  Cdc73p and Paf1p are found in a novel RNA polymerase II-containing complex distinct from the Srbp-containing holoenzyme , 1997, Molecular and cellular biology.

[25]  O. Nielsen,et al.  Assessment of pheromone production and response in fission yeast by a halo test of induced sporulation , 1994, Yeast.

[26]  Yang Li,et al.  A multiprotein mediator of transcriptional activation and its interaction with the C-terminal repeat domain of RNA polymerase II , 1994, Cell.

[27]  S. Triezenberg,et al.  Pattern of aromatic and hydrophobic amino acids critical for one of two subdomains of the VP16 transcriptional activator. , 1993, Proceedings of the National Academy of Sciences of the United States of America.

[28]  M. Sipiczki,et al.  The Schizosaccharomyces pombe sep15 + gene encodes a protein homologous to the Med8 subunit of the Saccharomyces cerevisiae transcriptional mediator complex , 2000, Current Genetics.

[29]  R. Kornberg,et al.  Mediator of transcriptional regulation. , 2000, Annual review of biochemistry.

[30]  J. Qin,et al.  A novel human SRB/MED-containing cofactor complex, SMCC, involved in transcription regulation. , 1999, Molecular cell.

[31]  D. Bushnell,et al.  The Med proteins of yeast and their function through the RNA polymerase II carboxy-terminal domain. , 1998, Genes & development.

[32]  Geoffrey J. Barton,et al.  JPred : a consensus secondary structure prediction server , 1999 .