The SAND domain protein ULTRAPETALA1 acts as a trithorax group factor to regulate cell fate in plants.
During development, trithorax group (trxG) chromatin remodeling complexes counteract repression by Polycomb group (PcG) complexes to sustain active expression of key regulatory genes. Although PcG complexes are well characterized in plants, little is known about trxG activities. Here we demonstrate that the Arabidopsis SAND (Sp100, AIRE-1, NucP41/75, DEAF-1) domain protein ULTRAPETALA1 (ULT1) functions as a trxG factor that counteracts the PcG-repressive activity of CURLY LEAF. In floral stem cells, ULT1 protein associates directly with the master homeotic locus AGAMOUS, inducing its expression by regulating its histone methylation status. Our analysis introduces a novel mechanism that mediates epigenetic switches controlling post-embryonic stem cell fates in plants.
Carles
Cristel C
CC
Plant Gene Expression Center, United States Department of Agriculture/University of California at Berkeley, Albany, California 94710, USA.
Fletcher
Jennifer C
JC
D026342:AGAMOUS Protein, Arabidopsis / Q000378:metabolism; D017360:Arabidopsis / Q000166:cytology* / Q000235:genetics / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D002454:Cell Differentiation; D044127:Epigenesis, Genetic; D018506:Gene Expression Regulation, Plant; D006657:Histones / Q000378:metabolism; D008745:Methylation; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*
D026342:AGAMOUS Protein, Arabidopsis; D029681:Arabidopsis Proteins; D006657:Histones; D014157:Transcription Factors; C500130:At4g28190 protein, Arabidopsis