ISWI Chromatin Remodeling Complex Evolutionary Conservation And Functional Analysis Of The Plant Embryo Development

Chromatin is the template of the epigenetic information.The nucleosome is thebasic unit of the chromatin. ATP-dependent remodeling complexes use the energy ofATP hydrolysis to change the status of the chromatin and finally alternate geneexpression through moving, assembling, replacing and ejecting nucleosomes. Thereare currently four conserved families of chromatin remodeling complexes ineukaryots: the SWI/SNF family, the ISWI family, the CHD family and the INO80family.The ISWI family remodeler complexes usually contain2to4subunits. The coresubunit ISWI proteins have a highly conserved structure, which contains aDNA-dependent ATPase domain and the HAND-SANT-SLIDE domains. By analyzingCHROMATIN REMODELING11(CHR11), an Arabidopsis thaliana ISWI protein, weshow that its SLIDE domain is responsible for direct interaction with anAtDDT-domain protein RINGLET1(RLT1). Moreover, we show that the human ISWIprotein SNF2H is capable of binding RLT1and DDP1, and the protein interaction isalso through the SLIDE domain. Together, our results indicate a conserved functionfor the SLIDE domain, which is required for the formation of DDT-ISWI complexes ineukaryotes during chromatin remodeling. The ATP-dependent remodeling complexeshave been previously shown to be crucial for development in Arabidopsis. Thechr11chr17double mutant and the CHD family mutant pkl exhibit multipledevelopmental defects. We show that the chr11chr17pkl triple mutant causesembryonic lethality, suggesting that ISWI and PKL act coordinately during theembryonic development.