The COP9 signalosome is essential for development of Drosophila melanogaster.
The COP9 signalosome (originally described as the COP9 complex) is an essential multi-subunit repressor of light-regulated development in plants [1] [2]. It has also been identified in mammals, though its role remains obscure [3] [4] [5]. This complex is similar to the regulatory lid of the proteasome and eIF3 [5] [9] [10] [11] [12] and several of its subunits are known to be involved in kinase signaling pathways [4] [6] [7] [8]. No proteins homologous to COP9 signalosome components were identified in the Saccharomyces cerevisiae genome, suggesting that the COP9 signalosome is specific for multi-cellular differentiation [13]. In order to reveal the developmental function of the COP9 signalosome in animals, we have isolated Drosophila melanogaster genes encoding eight subunits of the COP9 signalosome, and have shown by co-immunoprecipitation and gel-filtration analysis that these proteins are components of the Drosophila COP9 signalosome. Yeast two-hybrid assays indicated that several of these proteins interact, some through the PCI domain. Disruption of one of the subunits by either a P-element insertion or deletion of the gene caused lethality at the late larval or pupal stages. This lethality is probably a result of numerous pleiotropic effects. Our results indicate that the COP9 signalosome is conserved in invertebrates and that it has an essential role in animal development.
Freilich
S
S
Department of Plant Sciences Tel Aviv University, 69978, Tel Aviv, Israel.
Oron
E
E
Kapp
Y
Y
Nevo-Caspi
Y
Y
Orgad
S
S
Segal
D
D
Chamovitz
D A
DA
D000818:Animals; D017360:Arabidopsis / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D000075686:COP9 Signalosome Complex; D004331:Drosophila melanogaster / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism*; D017344:Genes, Insect; D019476:Insect Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D046912:Multiprotein Complexes; D010447:Peptide Hydrolases; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D020836:Protein Structure, Quaternary; D011506:Proteins; D015398:Signal Transduction; D013045:Species Specificity; D020798:Two-Hybrid System Techniques
D019476:Insect Proteins; D046912:Multiprotein Complexes; D010940:Plant Proteins; D011506:Proteins; D010447:Peptide Hydrolases; D000075686:COP9 Signalosome Complex