The first deltex null mutant indicates tissue-specific deltex-dependent Notch signaling in Drosophila.
Notch (N) is a single-pass transmembrane receptor. The N signaling pathway is an evolutionarily conserved mechanism that controls various cell-specification processes. Drosophila Deltex (Dx), a RING-domain E3 ubiquitin ligase, binds to the N intracellular domain, promotes N's endocytic trafficking to late endosomes, and was proposed to activate Suppressor of Hairless [Su(H)]-independent N signaling. However, it has been difficult to evaluate the importance of dx, because no null mutant of a dx family gene has been available in any organism. Here, we report the first null mutant allele of Drosophila dx. We found that dx was involved only in the subsets of N signaling, but was not essential for it in any developmental context. A strong genetic interaction between dx and Su(H) suggested that dx might function in Su(H)-dependent N signaling. Our epistatic analyses suggested that dx functions downstream of the ligands and upstream of activated Su(H). We also uncovered a novel dx activity that suppressed N signaling downstream of N.
Fuwa
Takashi J
TJ
Department of Biological Science and Technology, Tokyo University of Science, 2641 Yamazaki, 278-8510 Noda, Chiba, Japan.
Hori
Kazuya
K
Sasamura
Takeshi
T
Higgs
Jenny
J
Baron
Martin
M
Matsuno
Kenji
K
D000818:Animals; D001483:Base Sequence; D017931:DNA Primers; D004330:Drosophila; D029721:Drosophila Proteins / Q000235:genetics* / Q000378:metabolism*; D004705:Endocytosis; D008565:Membrane Proteins / Q000235:genetics*; D009030:Mosaicism; D009154:Mutation; D051880:Receptors, Notch / Q000378:metabolism*; D015398:Signal Transduction
D017931:DNA Primers; C086679:DX protein, Drosophila; D029721:Drosophila Proteins; D008565:Membrane Proteins; C497759:N protein, Drosophila; D051880:Receptors, Notch