title: Expression pattern of class I phosphoinositide 3-kinase and distribution of its product, phosphatidylinositol-3,4,5-trisphosphate, during Drosophila embryogenesis.
abstract: The class I phosphoinositide 3-kinase (PI3K) can be activated by a large variety of extracellular stimuli and is responsible for generating phosphatidylinositol-3,4,5-trisphosphate (PI(3,4,5)P(3)) from phosphatidylinositol-4,5-bisphosphate at the plasma membrane. The expression pattern of the class I PI3K and distribution of PI(3,4,5)P(3), visualized by its specific binding protein, GRP1-PH, were examined during Drosophila embryogenesis. We found that the RNA of Pi3K21B, encoding the Drosophila p60 regulatory subunit of the class I PI3Ks, was expressed maternally and expressed primarily in pole cells after cellularization until completion of germ band elongation. The RNA of Pi3K92E, encoding the Drosophila p110 catalytic subunit of the class I PI3Ks, was also expressed maternally. During gastrulation, its transcript level became lower and was slightly enriched in invaginating cells. Both Pi3K21B and Pi3K92E were expressed ubiquitously after germ band elongation and persisted during germ band shortening. PI(3,4,5)P(3) was distributed at the apical region of the invaginating cells during gastrulation. These findings suggest a possible involvement of class I PI3K and PI(3,4,5)P(3) in the regulation of invagination during gastrulation.
authors.affiliation: Department of Biochemistry, Gunma University Graduate School of Medicine, 3-39-22 Showa-machi, Maebashi, Gunma 371-8511, Japan.
authors.forename: Xin
authors.initials: X
authors.lastname: Xi
authors.affiliation: Department of Biochemistry, Gunma University Graduate School of Medicine, 3-39-22 Showa-machi, Maebashi, Gunma 371-8511, Japan.
authors.forename: Kazuaki
authors.initials: K
authors.lastname: Tatei
authors.affiliation: Department of Biochemistry, Gunma University Graduate School of Medicine, 3-39-22 Showa-machi, Maebashi, Gunma 371-8511, Japan.
authors.forename: Yumiko
authors.initials: Y
authors.lastname: Kihara
authors.affiliation: Department of Biochemistry, Gunma University Graduate School of Medicine, 3-39-22 Showa-machi, Maebashi, Gunma 371-8511, Japan. Electronic address: takashi_izumi@gunma-u.ac.jp.
authors.forename: Takashi
authors.initials: T
authors.lastname: Izumi
mesh_terms: D000199:Actins / Q000378:metabolism; D000818:Animals; D030801:Animals, Genetically Modified; D020134:Catalytic Domain; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism*; D004331:Drosophila melanogaster / Q000196:embryology* / Q000235:genetics; D047108:Embryonic Development; D005775:Gastrula / Q000378:metabolism; D020869:Gene Expression Profiling; D018507:Gene Expression Regulation, Developmental; D049452:Green Fluorescent Proteins / Q000378:metabolism; D017403:In Situ Hybridization; D007295:Inositol Phosphates / Q000737:chemistry*; D008055:Lipids / Q000737:chemistry; D018613:Microscopy, Confocal; D019869:Phosphatidylinositol 3-Kinases / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction
chemical_list: D000199:Actins; D029721:Drosophila Proteins; D007295:Inositol Phosphates; D008055:Lipids; C118500:inositol 3,4,5-trisphosphate; D049452:Green Fluorescent Proteins; D019869:Phosphatidylinositol 3-Kinases
keywords: Drosophila embryogenesis; Gastrulation; Phosphatidylinositol-3,4,5-trisphosphate; Phosphoinositide 3-kinase