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Full-Text Articles in Medical Molecular Biology
Fungal Mediator Tail Subunits Contain Classical Transcriptional Activation Domains, Zhongle Liu, Lawrence C. Myers
Fungal Mediator Tail Subunits Contain Classical Transcriptional Activation Domains, Zhongle Liu, Lawrence C. Myers
Dartmouth Scholarship
Classical activation domains within DNA-bound eukaryotic transcription factors make weak interactions with coactivator complexes, such as Mediator, to stimulate transcription. How these interactions stimulate transcription, however, is unknown. The activation of reporter genes by artificial fusion of Mediator subunits to DNA binding domains that bind to their promoters has been cited as evidence that the primary role of activators is simply to recruit Mediator. We have identified potent classical transcriptional activation domains in the C termini of several tail module subunits of Saccharomyces cerevisiae, Candida albicans, and Candida dubliniensis Mediator, while their N-terminal domains are necessary and sufficient for their …
Mediator Influences Telomeric Silencing And Cellular Life Span, Xuefeng Zhu, Beidong Liu, Jonas O. P. Carlsten, Jenny Beve, Thomas Nyström, Lawrence C. Myers, Claes M. Gustafsson
Mediator Influences Telomeric Silencing And Cellular Life Span, Xuefeng Zhu, Beidong Liu, Jonas O. P. Carlsten, Jenny Beve, Thomas Nyström, Lawrence C. Myers, Claes M. Gustafsson
Dartmouth Scholarship
The Mediator complex is required for the regulated transcription of nearly all RNA polymerase II-dependent genes. Here we demonstrate a new role for Mediator which appears to be separate from its function as a transcriptional coactivator. Mediator associates directly with heterochromatin at telomeres and influences the exact boundary between active and inactive chromatin. Loss of the Mediator Med5 subunit or mutations in Med7 cause a depletion of the complex from regions located near subtelomeric X elements, which leads to a change in the balance between the Sir2 and Sas2 proteins. These changes in turn result in increased levels of H4K16 …
The Nuclear Pore Complex And The Dead Box Protein Rat8p/Dbp5p Have Nonessential Features Which Appear To Facilitate Mrna Export Following Heat Shock, Christiane Rollenhagen, Christine A. Hodge, Charles N. Cole
The Nuclear Pore Complex And The Dead Box Protein Rat8p/Dbp5p Have Nonessential Features Which Appear To Facilitate Mrna Export Following Heat Shock, Christiane Rollenhagen, Christine A. Hodge, Charles N. Cole
Dartmouth Scholarship
Nuclear pore complexes (NPCs) play an essential role in RNA export. Nucleoporins required for mRNA export in Saccharomyces cerevisiae are found in the Nup84p and Nup82p subcomplexes of the NPC. The Nup82p subcomplex contains Nup82p, Rat7p/Nup159p, Nsp1p, Gle1p/Rss1p, and Rip1p/Nup42p and is found only on the cytoplasmic face of NPCs. Both Rat7p and Gle1p contain binding sites for Rat8p/Dbp5p, an essential DEAD box protein and putative RNA helicase. Rip1p interacts directly with Gle1p and is the only protein known to be essential for mRNA export after heat shock but not under normal growth conditions. We report that in cells lacking …
Characterization Of The Formate (For) Locus, Which Encodes The Cytosolic Serine Hydroxymethyltransferase Of Neurospora Crassa., C. Robertson Mcclung, Cynthia R. Davis, Karen M. Page, Sylvia A. Denome
Characterization Of The Formate (For) Locus, Which Encodes The Cytosolic Serine Hydroxymethyltransferase Of Neurospora Crassa., C. Robertson Mcclung, Cynthia R. Davis, Karen M. Page, Sylvia A. Denome
Dartmouth Scholarship
Serine hydroxymethyltransferase (SHMT) occupies a central position in one-carbon (C1) metabolism, catalyzing the reaction of serine and tetrahydrofolate to yield glycine and 5,10-methylenetetrahydrofolate. Methylenetetrahydrofolate serves as a donor of C1 units for the synthesis of numerous compounds, including purines, thymidylate, lipids, and methionine. We provide evidence that the formate (for) locus of Neurospora crassa encodes cytosolic SHMT. The for+ gene was localized to a 2.8-kb BglII fragment by complementation (restoration to formate-independent growth) of a strain carrying a recessive for allele, which confers a growth requirement for formate. The for+ gene encodes a polypeptide of 479 amino acids which shows …