title: Characterization of EMU, the Arabidopsis homolog of the yeast THO complex member HPR1.
abstract: Diverse and precise control is essential for eukaryotic gene expression. This is accomplished through the recruitment of a myriad of proteins to a nascent messenger RNA (mRNA) to mediate modifications, such as capping, splicing, 3'-end processing, and export. Despite being important for every cell, however, the mechanism by which the formation of diverse messenger ribonucleoprotein (mRNP) particles contributes to maintaining intricate systems in the multicellular organism remains incompletely defined. We identified and characterized a mutant gene named erecta mRNA under-expressed (emu) that leads to the defective mRNA accumulation of ERECTA, a developmental regulator in the model plant Arabidopsis thaliana. EMU encodes a protein homologous to a component of the THO complex that is required for the generation of functional mRNPs. Further analysis suggested that EMU is genetically associated with SERRATE, HYPONASTIC LEAVES1, and ARGONAUTE1, which are required for proper RNA maturation or action. Furthermore, mutations in another THO-related gene led to embryonic lethality. These findings support the presence and importance of the THO-related complex in plants as well as yeast and vertebrates.
authors.affiliation: Department of Biological Sciences, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033 Japan.
authors.forename: Chihiro
authors.initials: C
authors.lastname: Furumizu
authors.forename: Hirokazu
authors.initials: H
authors.lastname: Tsukaya
authors.forename: Yoshibumi
authors.initials: Y
authors.lastname: Komeda
mesh_terms: D017360:Arabidopsis / Q000235:genetics* / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism*; D009687:Nuclear Proteins / Q000235:genetics; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism; D012326:RNA Splicing; D012333:RNA, Messenger / Q000378:metabolism; D011956:Receptors, Cell Surface / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics
chemical_list: D029681:Arabidopsis Proteins; C552050:EMU protein, Arabidopsis; C063494:HPR1 protein, S cerevisiae; D009687:Nuclear Proteins; D012333:RNA, Messenger; D011956:Receptors, Cell Surface; D029701:Saccharomyces cerevisiae Proteins; C457763:ER protein, Arabidopsis; D017346:Protein Serine-Threonine Kinases