TY - JOUR
T1 - COP9 signalosome subunits 4 and 5 regulate mulitple pleiotropic pathways in Drosophila melanogaster
AU - Oron, Efrat
AU - Mannervik, Mattias
AU - Rencus, Sigal
AU - Harari-Steinberg, Orit
AU - Neuman-Silberberg, Shira
AU - Segal, Daniel
AU - Chamovitz, Daniel A.
PY - 2002/10/1
Y1 - 2002/10/1
N2 - The COP9 signalosome (CSN) is an essential eight-subunit repressor of light-regulated development in Arabidopsis. This complex has also been identified in animals, though its developmental role remains obscure. CSN subunits have been implicated in various cellular processes, suggesting a possible role for the CSN as an integrator of multiple signaling pathways. In order to elucidate the function of the CSN in animals, a Drosophila model system has previously been established. Gel-filtration analysis with antibodies against CSN subunits 4, 5 and 7 revealed that these proteins act as a complex in Drosophila that is similar in size to the plant and mammalian complexes. Null mutations in either one of two subunits, CSN4 or CSN5, are larval lethal. Successful embryogenesis appears to be a consequence of maternal contribution of the complex. Biochemical analysis indicates that the different subunits are found in both CSN-dependent and CSN-independent forms, and that these forms are differentially affected by the mutations. Phenotypic characterization of these two mutants indicates that they show both shared and unique phenotypes, which suggest specific roles for each subunit. Both mutants have defective oocyte and embryo patterning, and defects in response to DNA damage, while csn5 mutants develop melanotic tumors and csn4 mutants have phenotypes reminiscent of defects in ecdysone signaling.
AB - The COP9 signalosome (CSN) is an essential eight-subunit repressor of light-regulated development in Arabidopsis. This complex has also been identified in animals, though its developmental role remains obscure. CSN subunits have been implicated in various cellular processes, suggesting a possible role for the CSN as an integrator of multiple signaling pathways. In order to elucidate the function of the CSN in animals, a Drosophila model system has previously been established. Gel-filtration analysis with antibodies against CSN subunits 4, 5 and 7 revealed that these proteins act as a complex in Drosophila that is similar in size to the plant and mammalian complexes. Null mutations in either one of two subunits, CSN4 or CSN5, are larval lethal. Successful embryogenesis appears to be a consequence of maternal contribution of the complex. Biochemical analysis indicates that the different subunits are found in both CSN-dependent and CSN-independent forms, and that these forms are differentially affected by the mutations. Phenotypic characterization of these two mutants indicates that they show both shared and unique phenotypes, which suggest specific roles for each subunit. Both mutants have defective oocyte and embryo patterning, and defects in response to DNA damage, while csn5 mutants develop melanotic tumors and csn4 mutants have phenotypes reminiscent of defects in ecdysone signaling.
KW - COP9 signalosome
KW - Drosophila
KW - Embryo development
KW - Maternal effect
KW - Oogenesis
UR - http://www.scopus.com/inward/record.url?scp=0036800232&partnerID=8YFLogxK
U2 - 10.1242/dev.129.19.4399
DO - 10.1242/dev.129.19.4399
M3 - Article
AN - SCOPUS:0036800232
SN - 0950-1991
VL - 129
SP - 4399
EP - 4409
JO - Development (Cambridge)
JF - Development (Cambridge)
IS - 19
ER -