Loss and gain of domains during evolution of cut superclass homeobox genes.
The cut superclass of homeobox genes has been divided into three classes: CUX, ONECUT and SATB. Given the various completed genomes, we have now made a comprehensive survey. We find that there are only two cut domain containing genes in Drosophila, one CUX and one ONECUT type. Caenorhabditis elegans has undergone an expansion of the ONECUT subclass genes and has a gene cluster with three ONECUT class genes, one of which has lost the cut domain. Two of these genes contain a conserved sequence motif, termed OCAM, which also occurs in another gene in C. elegans this motif seems to be nematode specific. A recently uncovered C. elegans CUX gene has sequence conservation in its amino-terminus with vertebrate CUX proteins. Further, the 5' end of this gene containing the conserved region can undergo alternative splicing to give rise to a protein with a different carboxy-terminus lacking the cut- and homeodomain. This protein is conserved in its entirety with vertebrate genes termed CASP--which are also alternative splice products of the CUX genes--and with plant and fungal genes. The highly divergent SATB genes share a conserved amino terminal domain, COMPASS, with the Drosophila defective proventriculus gene and a C. elegans ORF. These two "COMPASS" family genes encode two highly divergent homeodomains, may be homologues of the SATB genes and thus probably belong to the cut superclass, too.
Bürglin
Thomas R
TR
Division of Cell Biology, Biozentrum, University of Basel, Switzerland. thomas.burglin@biosci.ki.se
Cassata
Giuseppe
G
D017398:Alternative Splicing; D000595:Amino Acid Sequence; D000818:Animals; D017173:Caenorhabditis elegans; D018076:DNA, Complementary / Q000378:metabolism; D019992:Databases as Topic; D029721:Drosophila Proteins; D004331:Drosophila melanogaster; D019143:Evolution, Molecular; D018398:Homeodomain Proteins / Q000235:genetics*; D008957:Models, Genetic; D008969:Molecular Sequence Data; D009419:Nerve Tissue Proteins / Q000235:genetics*; D009687:Nuclear Proteins / Q000235:genetics*; D010802:Phylogeny; D017434:Protein Structure, Tertiary; D012097:Repressor Proteins / Q000235:genetics*; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D015534:Trans-Activators / Q000235:genetics*; D014157:Transcription Factors
D018076:DNA, Complementary; D029721:Drosophila Proteins; D018398:Homeodomain Proteins; D009419:Nerve Tissue Proteins; D009687:Nuclear Proteins; D012097:Repressor Proteins; D015534:Trans-Activators; D014157:Transcription Factors; C066381:ct protein, Drosophila; C418486:onecut protein, Drosophila