Global regulation of Hox gene expression in C. elegans by a SAM domain protein.
Polycomb group (PcG)-mediated repression of C. elegans Hox genes has not been demonstrated, and genes homologous to components of one of the PcG complexes (PRC1) have not been identified in the C. elegans genome. We find that a mechanism of general Hox gene repression exists in C. elegans, carried out in part by SOP-2, a protein related to, but not orthologous with, any PcG protein. sop-2 mutations lead to widespread ectopic expression of Hox genes and homeotic transformations. SOP-2 contains a SAM domain, a self-associating protein domain found in other repressors, including a core component of PRC1 and ETS transcription factors. Phylogenetic analysis indicates that this domain is more closely related to those of the ETS family than to those of PcG proteins. The results suggest that global repression of Hox genes has been taken over by a different branch of the SAM domain family during the evolution of nematodes.
Zhang
Hong
H
Department of Molecular Genetics, Albert Einstein College of Medicine, Bronx, NY 10461, USA. zhangh@helix.mgh.harvard.edu
Azevedo
Ricardo B R
RB
Lints
Robyn
R
Doyle
Christina
C
Teng
Yingqi
Y
Haber
Daniel
D
Emmons
Scott W
SW
D000595:Amino Acid Sequence; D000818:Animals; D017173:Caenorhabditis elegans / Q000235:genetics*; D029742:Caenorhabditis elegans Proteins; D019143:Evolution, Molecular; D018507:Gene Expression Regulation, Developmental; D017238:Genes, Helminth; D005801:Genes, Homeobox; D007814:Larva; D008297:Male; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009154:Mutation; D010641:Phenotype; D010802:Phylogeny; D020161:Physical Chromosome Mapping; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D011993:Recombinant Fusion Proteins / Q000737:chemistry; D012097:Repressor Proteins / Q000737:chemistry*; D017386:Sequence Homology, Amino Acid
D029742:Caenorhabditis elegans Proteins; D011993:Recombinant Fusion Proteins; D012097:Repressor Proteins; C475806:Sop-2 protein, C elegans