Characterization of the split ends-like gene spenito reveals functional antagonism between SPOC family members during Drosophila eye development.
The novel family of SPOC domain proteins is composed of broadly conserved nuclear factors that fall into two subclasses, termed large and small, based on protein size. Members of the large subgroup, which includes Drosophila SPEN and human SHARP, have been characterized as transcriptional corepressors acting downstream of a variety of essential cell signaling pathways, while those of the small subclass have remained largely unstudied. Since SPEN has been implicated in Drosophila eye development, and the small SPOC protein NITO is also expressed in the developing eye, we have used this context to perform a structure-function analysis of NITO and to examine the relationship between the two SPOC family subclasses. Our results demonstrate that the phenotypes obtained from overexpressing NITO share striking similarity to those associated with loss of spen. Dosage-sensitive genetic interactions further support a model of functional antagonism between NITO and SPEN during Drosophila eye development. These results suggest that large and small SPOC family proteins may have opposing functions in certain developmental contexts.
Department of Biology, Massachusetts Institute of Technology, Cambridge 02142, USA.
Jennifer
J
Jemc
Ilaria
I
Rebay
D000595:Amino Acid Sequence; D000818:Animals; D002470:Cell Survival; D017124:Conserved Sequence / Q000235:genetics; D029721:Drosophila Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D004331:Drosophila melanogaster / Q000033:anatomy & histology / Q000254:growth & development* / Q000378:metabolism*; D005123:Eye / Q000033:anatomy & histology / Q000166:cytology / Q000254:growth & development* / Q000648:ultrastructure; D015870:Gene Expression; D018398:Homeodomain Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D005810:Multigene Family / Q000235:genetics*; D009687:Nuclear Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D017434:Protein Structure, Tertiary; D016601:RNA-Binding Proteins
D029721:Drosophila Proteins; D018398:Homeodomain Proteins; C512063:NITO protein, Drosophila; D009687:Nuclear Proteins; D016601:RNA-Binding Proteins; C402387:Spen protein, Drosophila