A CACGTG motif of the Antirrhinum majus chalcone synthase promoter is recognized by an evolutionarily conserved nuclear protein.

The Wingless (Wg)/Wnt signal transduction pathway regulates many developmental processes through a complex of Armadillo(Arm)/β-catenin and the HMG-box transcription factors of the Tcf family. We report the identification of a new component, Pygopus (Pygo), that plays an essential role in the Wg/Wnt signal transduction pathway. We show that Wg signaling is diminished during embryogenesis and imaginal disc development in the absence of pygo activity. Pygo acts downstream or in parallel with Arm to regulate the nuclear function of Arm protein. pygo encodes a novel and evolutionarily conserved nuclear protein bearing a PHD finger that is essential for its activity. We further show that Pygo can form a complex with Arm in vivo and possesses a transcription activation domain(s). Finally, we have isolated a Xenopus homolog of pygo (Xpygo). Depletion of maternal Xpygo by antisense deoxyoligonucleotides leads to ventralized embryonic defects and a reduction of the expression of Wnt target genes. Together, these findings demonstrate that Pygo is an essential component in the Wg/Wnt signal transduction pathway and is likely to act as a transcription co-activator required for the nuclear function of Arm/β-catenin.

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The 17-kb Tam1 element of Antirrhinum majus induces a 3-bp duplication upon integration into the chalcone synthase gene

The EMBO Journal ◽

10.1002/j.1460-2075.1984.tb01921.x ◽

1984 ◽

Vol 3 (5) ◽

pp. 1015-1019 ◽

Cited By ~ 74

Author(s):

Ulla Bonas ◽

Hans Sommer ◽

Heinz Saedler

Keyword(s):

Chalcone Synthase ◽

Antirrhinum Majus ◽

Chalcone Synthase Gene

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Xio is a component of the Drosophila sex determination pathway and RNA N6-methyladenosine methyltransferase complex

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1720945115 ◽

2018 ◽

Vol 115 (14) ◽

pp. 3674-3679 ◽

Cited By ~ 34

Author(s):

Jian Guo ◽

Hong-Wen Tang ◽

Jing Li ◽

Norbert Perrimon ◽

Dong Yan

Keyword(s):

Alternative Splicing ◽

Chemical Modification ◽

Sex Determination ◽

Unknown Function ◽

Nuclear Protein ◽

Loss Of Function ◽

Splicing Defect ◽

Evolutionarily Conserved ◽

Sex Lethal

N6-methyladenosine (m6A), the most abundant chemical modification in eukaryotic mRNA, has been implicated in Drosophila sex determination by modifying Sex-lethal (Sxl) pre-mRNA and facilitating its alternative splicing. Here, we identify a sex determination gene, CG7358, and rename it xio according to its loss-of-function female-to-male transformation phenotype. xio encodes a conserved ubiquitous nuclear protein of unknown function. We show that Xio colocalizes and interacts with all previously known m6A writer complex subunits (METTL3, METTL14, Fl(2)d/WTAP, Vir/KIAA1429, and Nito/Rbm15) and that loss of xio is associated with phenotypes that resemble other m6A factors, such as sexual transformations, Sxl splicing defect, held-out wings, flightless flies, and reduction of m6A levels. Thus, Xio encodes a member of the m6A methyltransferase complex involved in mRNA modification. Since its ortholog ZC3H13 (or KIAA0853) also associates with several m6A writer factors, the function of Xio in the m6A pathway is likely evolutionarily conserved.

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