Multifunctional factor ENY2 is associated with the THO complex and promotes its recruitment onto nascent mRNA

Abstract

Metazoan E(y)2/ENY2 is a multifunctional protein important for transcription activation and mRNA export, being a component of SAGA/TFTC and the mRNA export complex AMEX. Here, we show that ENY2 in Drosophila is also stably associated with THO, the complex involved in mRNP biogenesis. The ENY2-THO complex is required for normal Drosophila development, functioning independently on SAGA and AMEX. ENY2 and THO arrive on the transcribed region of the hsp70 gene after its activation, and ENY2 plays an important role in THO recruitment. ENY2 and THO show no direct association with elongating RNA polymerase II. Recruitment of ENY2 and THO occurs by their loading onto nascent mRNA, apparently immediately after its synthesis, while the AMEX component Xmas-2 is loaded onto mRNA at a later stage. Knockdown of either ENY2 or THO, but not SAGA or AMEX, affects the processing of the transcript's 39 end. Thus, ENY2, as a shared subunit of several protein complexes governing the sequential steps of gene expression, plays an important role in the coordination of these steps.[Keywords: THO; mRNA export; mRNP formation; gene expression; protein complex; ENY2] Supplemental material is available at http://www.genesdev.org.

The THO complex is required for nucleolar integrity in Drosophila spermatocytes

“…Recent studies using conditional knockout or a hypomorphic mutant mouse model have provided evidence that the THO complex has specific roles in cell differentiation during development (Mancini et al, 2010;Wang et al, 2009;Wang et al, 2007). It has also recently been reported that the Drosophila THO complex is required for normal development through collaboration with E(Y)2 (or ENY2), a multifunctional protein important for transcription activation and mRNA export (Kopytova et al, 2010).…”

“…Primary antibodies used in this study were: anti-THOC7 (Kim et al, 2011) at 1:1000, anti-HPR1 (Rehwinkel et al, 2004) at 1:100, anti-THO2 (Rehwinkel et al, 2004) at 1:100, anti-THOC5 (Kopytova et al, 2010) at 1:100 and anti-Fibrillarin (38F3; Santa Cruz, sc-56676) at 1:50. The secondary antibodies Alexa 546-conjugated goat anti-rabbit (1:500) and Alexa 488-conjugated goat anti-mouse (1:500) were purchased from Molecular Probes.…”

Evidence that the Arabidopsis Ubiquitin C-terminal Hydrolases 1 and 2 associate with the 26S proteasome and the TREX-2 complex

“…It is tethered to the inner side of the nuclear pore complex (NPC) via AtNUP1 (also named NUP136) which is a plant-specific nucleoporin. 14,17 Similar TREX-2 homologs have also been identified in fruit flies 18 and humans. 19 Here, we present evidence demonstrating a physical link between Arabidopsis UCH1/UCH2 and the 26S proteasome lid complex, as well as to the TREX-2 complex.…”

Coupling pre-mRNA processing to transcription on the RNA factory assembly line

“…95 However, the association of ENY2 with components of THO instead of TREX-2 suggests that Sus1/ENY2 may participate in mRNA export, in conjunction with similar but somewhat different complexes, in higher eukaryotic cells. 96 Nevertheless, as compared with yeast, the detailed function of TREX and related complexes in higher eukaryotes is less clear and requires much more investigation.…”