The nematode homologue of Mediator complex subunit 28, F28F8.5, is a critical regulator of C. elegans development

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1 Biocev, First Faculty of Medicine, Charles University, Prague, Czech Republic
2 Department of Pathology, Third Faculty of Medicine, Charles University, Prague, Czech Republic
3 Biocev, First Faculty of Medicine, Charles University in Prague, Prague, Czech Republic
4 Imaging Methods Core Facility, BIOCEV, Faculty of Science, Charles University, Prague, Czech Republic
5 Laboratory of Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland, USA
6 Metabolic Research Laboratories, Wellcome Trust-Medical Research Council Institute of Metabolic Science, University of Cambridge, Cambridge, United Kingdom
DOI
10.7287/peerj.preprints.2530v2
Published
Accepted
Subject Areas
Cell Biology, Developmental Biology, Evolutionary Studies, Molecular Biology
Keywords
Gene expression regulation, Caenorhabditis elegans, Development, Evolution, Mediator complex, MED28
Copyright
© 2016 Kostrouchová et al.
Licence
This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, reproduction and adaptation in any medium and for any purpose provided that it is properly attributed. For attribution, the original author(s), title, publication source (PeerJ Preprints) and either DOI or URL of the article must be cited.
Cite this article
Kostrouchová M, Kostrouch D, Chughtai AA, Kaššák F, Novotný JP, Kostrouchová V, Benda A, Krause MW, Saudek V, Kostrouchová M, Kostrouch Z. 2016. The nematode homologue of Mediator complex subunit 28, F28F8.5, is a critical regulator of C. elegans development. PeerJ Preprints 4:e2530v2

Abstract

The evolutionarily conserved Mediator complex is a critical player in regulating transcription. Comprised of approximately two dozen proteins, Mediator integrates diverse regulatory signals through direct protein-protein interactions that, in turn, modulate the influence of Mediator on RNA Polymerase II activity. One Mediator subunit, MED28, is known to interact with cytoplasmic structural proteins, providing a potential direct link between cytoplasmic dynamics and the control of gene transcription. Although identified in many animals and plants, MED28 is not present in yeast; no bona fide MED28 has been described previously in C. elegans. Here, we identify bioinformatically F28F8.5, an uncharacterized predicted protein, as the nematode homologue of MED28. As in other metazoa, F28F8.5 has dual nuclear and cytoplasmic localization and plays critical roles in the regulation of development. F28F8.5 is a vital gene and its null mutants have severely malformed gonads and do not reproduce. Our results indicate that F28F8.5 is a homologue of MED28 and suggest that the potential to link cytoplasmic and nuclear events is conserved between MED28 vertebrate and nematode homologues.

Author Comment

Version v2 reflects the WormBase newly approved name of F28F8.5 which is MDT-28, rather than MDTH-28, which was suggested in version v1 (lines 406 to 408).

Supplemental Information

Sequences of multiple sequence alignment of selected metazoan homologues of MED28 with F28F8.5a

Sequences in FastA format for direct submission to Promals.

DOI: 10.7287/peerj.preprints.2530v2/supp-1

Expression of F28F8.5a/b::GFP from a transgene including internal promoter and present in transgenic animals as extrachromosomal arrays

Panels A, C, E and G show images in Nomarski optics and corresponding panels B, D, F and H in GFP fluorescence. In the twofold stage (panels A and B, C and D), the transgene is expressed in epidermal cells - seam cells (panels B and D). The transgene is localized both in the cytoplasm and nuclei (panel B, arrowheads) or is found accented in nuclei (panel D, arrowheads, contrast and brightness were increased +20, original picture is provided as Raw Data). In the threefold embryo (panels E and F), the transgene is progressively localized in nuclei as well as in the cytoplasm of epidermal cells, arrowheads. Panels G and H show a complete L1 larva before hatching with the expression of the transgene predominantly in the cytoplasm of intestinal cells (arrow). Panels L, M and N show an adult hermaphrodite animal with F28F8.5::GFP fluorescence in nuclei of enterocytes and in the excretory cell and its channels (arrows). Panels O to Q show a proximal part of the body of a hermaphrodite L2 stage in confocal microscopy (panels P and Q that are parallel optical planes) and overview image in Nomarski optics (panel O). Arrows indicate excretory channels and the body of the excretory cell (lower arrow in panel Q). Arrowheads indicate nuclei of enterocytes with accumulated F28F8.5::GFP in a nuclear compartment surrounding the large nucleoli. F28F8.5::GFP is also localized diffusely in the cytoplasm of enterocytes. Bars represent 10 µm.

DOI: 10.7287/peerj.preprints.2530v2/supp-2

Raw images for Fig.2

Unprocessed images that were used for preparation of Fig.2

DOI: 10.7287/peerj.preprints.2530v2/supp-4