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Divergent Evolution of CHD3 Proteins Resulted in MOM1 Refining Epigenetic Control in Vascular Plants

By Marian Čaikovski, Chotika Yokthongwattana, Yoshiki Habu, Taisuke Nishimura, Olivier Mathieu and Jerzy Paszkowski


Arabidopsis MOM1 is required for the heritable maintenance of transcriptional gene silencing (TGS). Unlike many other silencing factors, depletion of MOM1 evokes transcription at selected loci without major changes in DNA methylation or histone modification. These loci retain unusual, bivalent chromatin properties, intermediate to both euchromatin and heterochromatin. The structure of MOM1 previously suggested an integral nuclear membrane protein with chromatin-remodeling and actin-binding activities. Unexpected results presented here challenge these presumed MOM1 activities and demonstrate that less than 13% of MOM1 sequence is necessary and sufficient for TGS maintenance. This active sequence encompasses a novel Conserved MOM1 Motif 2 (CMM2). The high conservation suggests that CMM2 has been the subject of strong evolutionary pressure. The replacement of Arabidopsis CMM2 by a poplar motif reveals its functional conservation. Interspecies comparison suggests that MOM1 proteins emerged at the origin of vascular plants through neo-functionalization of the ubiquitous eukaryotic CHD3 chromatin remodeling factors. Interestingly, despite the divergent evolution of CHD3 and MOM1, we observed functional cooperation in epigenetic control involving unrelated protein motifs and thus probably diverse mechanisms

Topics: Research Article
Publisher: Public Library of Science
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    1. (2006). A bivalent chromatin structure marks key developmental genes in embryonic stem cells.
    2. (2006). Brehm A
    3. (1997). Characterization of the CHD family of proteins.
    4. (1998). Chromatin deacetylation by an ATP-dependent nucleosome remodelling complex.
    5. (2000). Disruption of the plant gene MOM releases transcriptional silencing of methylated genes.
    6. (1999). Distinct mechanisms promote polarity establishment in carpels of Arabidopsis. Cell 99: 199–209. 1 8 .K h a t t a kS
    7. (1998). dMi-2, a hunchback-interacting protein that functions in polycomb repression.
    8. (2000). DNA methylation and chromatin structure affect transcriptional and post-transcriptional transgene silencing in Arabidopsis.
    9. (2000). Endogenous targets of transcriptional gene silencing in Arabidopsis.
    10. (2006). Epigenetic regulation of transcription in intermediate heterochromatin.
    11. (2000). Finding nuclear localization signals.
    12. (1998). Floral dip: a simplified method for Agrobacteriummediated transformation of Arabidopsis thaliana.
    13. (2005). Gardening the genome: DNA methylation in Arabidopsis thaliana.
    14. (2005). Genome Sequencing Project
    15. (1987). GUS fusions: betaglucuronidase as a sensitive and versatile gene fusion marker in higher plants.
    16. (2006). MOM1 mediates DNAmethylation-independent silencing of repetitive sequences in Arabidopsis.
    17. (1999). PICKLE is a CHD3 chromatin-remodeling factor that regulates the transition from embryonic to vegetative development in Arabidopsis.P r o cN a t lA c a dS c iUSA9 6 :
    18. (2006). PICKLE is required for SOLITARYROOT/IAA14-mediated repression of ARF7 and ARF19 activity during Arabidopsis lateral root initiation.
    19. (1996). SEAVIEW and PHYLO_WIN: two graphic tools for sequence alignment and molecular phylogeny.
    20. (2007). SHREC, an effector complex for heterochromatic transcriptional silencing.
    21. (2002). SPLAYED, a novel SWI/SNF ATPase homolog, controls reproductive development in Arabidopsis.
    22. (2005). Structure of the SWI2/SNF2 chromatin-remodeling domain of eukaryotic Rad54.
    23. (2006). The genome of black cottonwood, Populus trichocarpa
    24. (2007). The role of chromatinremodeling factor PKL in balancing osmotic stress responses during Arabidopsis seed germination.
    25. (2007). Transgenerational stability of the Arabidopsis epigenome is coordinated by CG methylation.
    26. (2004). TREEFINDER: a powerful graphical analysis environment for molecular phylogenetics.
    27. (2003). Two means of transcriptional reactivation within heterochromatin.
    28. (2002). Two regulatory levels of transcriptional gene silencing in Arabidopsis.

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