Caenorhabditis elegans Mediator complexes are required for developmental-specific transcriptional activation

Caenorhabditis elegans Mediator complexes are required for developmental-specific transcriptional activation

^*Department of Biology, Yonsei University, 134 Shinchon-dong, Seodaemun-ku, Seoul, 120-749, Korea; and ^‡Center for Transcriptional Regulation, Sungkyunkwan University School of Medicine, Chunchun-dong 300, Jangan-ku, Suwon-si, Kyunggi-do, 440-746, Korea

Communicated by Roger D. Kornberg, Stanford University School of Medicine, Stanford, CA (received for review July 12, 1999)

Abstract

Mediator proteins are required for transcriptional regulation of most genes in yeast. Mammalian Mediator homologs also function as transcriptional coactivators in vitro; however, their physiological role in gene-specific transcription is not yet known. To determine the role of Mediator proteins in the development of complex organisms, we purified putative Mediator complexes from Caenorhabditis elegans and analyzed their phenotypes in vivo. C. elegans Mediator homologs were assembled into two multiprotein complexes. RNA interference assays showed that the CeMed6, CeMed7, and CeMed10/CeNut2 gene products are required for the expression of developmentally regulated genes, but are dispensable for expression of the ubiquitously expressed genes tested in this study. Therefore, the gene-specific function of Mediator as an integrator of transcriptional regulatory signals is evolutionarily conserved and is essential for C. elegans development.

Footnotes

↵ † J.Y.K. and J.M.P. contributed equally to this work.
↵ § To whom reprint requests should be addressed. E-mail: yjkim{at}smc.samsung.co.kr or leej{at}yonsei.ac.kr.
Abbreviations:

TAF,

TATA-binding protein (TBP)-associated factor;

pol II,

RNA polymerase II;

RNAi,

RNA interference;

dsRNA,

double-stranded RNA;

dsRNAi,

dsRNA interference;

GFP,

green fluorescent protein