Biomaterial Database

Novel role for mediator complex subunit Srb5/Med18 in termination of transcription. 2011

Banupriya Mukundan, and Athar Ansari

Department of Biological Sciences, Wayne State University, Detroit, Michigan 48202, USA.

Mediator complex functions at the recruitment as well as the post-recruitment steps of transcription. Here we provide evidence for a novel role of Mediator in termination of transcription. Mediator subunit Srb5/Med18 cross-links to the 5' and 3' ends of INO1 and CHA1. In srb5(-) cells, recruitment of TATA-binding protein (TBP) and transcription factor IIB (TFIIB) onto the promoter of these genes remained unaffected, but cross-linking of the cleavage-polyadenylation factors Rna15 and Pta1 toward the 3' end of genes was compromised. In these cells, RNA polymerase II accumulated near the 3' end of genes and beyond. Transcription run-on analysis confirmed a transcription readthrough phenotype in the absence of Srb5/Med18. These results strongly suggest that Mediator subunit Srb5/Med18 is required for proper termination of transcription of a subset of genes in budding yeast.

UI	MeSH Term	Description	Entries
D012319	RNA Polymerase II	A DNA-dependent RNA polymerase present in bacterial, plant, and animal cells. It functions in the nucleoplasmic structure and transcribes DNA into RNA. It has different requirements for cations and salt than RNA polymerase I and is strongly inhibited by alpha-amanitin. EC 2.7.7.6.	DNA-Dependent RNA Polymerase II,RNA Pol II,RNA Polymerase B,DNA Dependent RNA Polymerase II
D012441	Saccharomyces cerevisiae	A species of the genus SACCHAROMYCES, family Saccharomycetaceae, order Saccharomycetales, known as "baker's" or "brewer's" yeast. The dried form is used as a dietary supplement.	Baker's Yeast,Brewer's Yeast,Candida robusta,S. cerevisiae,Saccharomyces capensis,Saccharomyces italicus,Saccharomyces oviformis,Saccharomyces uvarum var. melibiosus,Yeast, Baker's,Yeast, Brewer's,Baker Yeast,S cerevisiae,Baker's Yeasts,Yeast, Baker
D014158	Transcription, Genetic	The biosynthesis of RNA carried out on a template of DNA. The biosynthesis of DNA from an RNA template is called REVERSE TRANSCRIPTION.	Genetic Transcription
D056892	Mediator Complex	A large protein complex which acts as a signaling adaptor protein that allows communication between the various regulatory and functional components of GENETIC TRANSCRIPTION including DNA POLYMERASE II; GENERAL TRANSCRIPTION FACTORS; and TRANSCRIPTION FACTORS that are bound to upstream ENHANCER ELEMENTS. The mediator complex was originally studied in YEAST where at least 21 subunits were identified. Many of the yeast subunits are homologs to proteins in higher organisms that are found associated with specific nuclear receptors such as THYROID HORMONE RECEPTORS and VITAMIN D RECEPTORS.	Mediator Transcription Complex,Mediator-Like Complex,Mediator-Like Complexes,TR-Associated Protein (TRAP) Complex,TRAP (Thyroid Hormone Associated Protein) Complex,Thyroid Hormone-Associated Protein Complex,Mediator Like Complex,Mediator Like Complexes,Thyroid Hormone Associated Protein Complex
D029701	Saccharomyces cerevisiae Proteins	Proteins obtained from the species SACCHAROMYCES CEREVISIAE. The function of specific proteins from this organism are the subject of intense scientific interest and have been used to derive basic understanding of the functioning similar proteins in higher eukaryotes.	Baker's Yeast Proteins,S cerevisiae Proteins