کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
10824335 | 1062358 | 2005 | 13 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Ca2+ signaling in prothoracicotropic hormone-stimulated prothoracic gland cells of Manduca sexta: Evidence for mobilization and entry mechanisms
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کلمات کلیدی
موضوعات مرتبط
علوم زیستی و بیوفناوری
علوم کشاورزی و بیولوژیک
دانش حشره شناسی
پیش نمایش صفحه اول مقاله
چکیده انگلیسی
Prothoracicotropic hormone (PTTH) stimulates ecdysteroidogenesis in lepidopteran prothoracic glands (PGs), thus indirectly controlling molting and metamorphosis. PTTH triggers a signal transduction cascade in PGs that involves an early influx of Ca2+. Although the importance of Ca2+ has been long known, the mechanism(s) of PTTH-stimulated changes in cytoplasmic Ca2+ [Ca2+]i are not yet well understood. PGs from the fifth instar of Manduca sexta were exposed to PTTH in vitro. The resultant changes in [Ca2+]i were measured using ratiometric analysis of a fura-2 fluorescence signal in the presence and absence of inhibitors of specific cellular signaling mechanisms. The phospholipase C (PLC) inhibitor U-73122 nearly abolished the PTTH-stimulated increase in [Ca2+]i, as well as PTTH-stimulated ecdysteroidogenesis and extracellular-signal regulated kinase phosphorylation, thus establishing a role for PLC and implicating inositol trisphosphate (IP3) in PTTH signal transduction. Two antagonists of the IP3 receptor, 2-APB and TMB-8, likewise blocked the [Ca2+]i response by a mean of 92%. We describe for the first time the presence of Ca2+ oscillations in PTTH-stimulated cells in Ca2+-free medium. External Ca2+ entered PG cells via at least two routes: store-operated (capacitative) Ca2+ entry channels and L-type voltage-gated Ca2+ channels. We propose that PTTH initiates a transductory cascade typical of many G-protein coupled receptors, involving both Ca2+ mobilization and entry pathways.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Insect Biochemistry and Molecular Biology - Volume 35, Issue 4, April 2005, Pages 263-275
Journal: Insect Biochemistry and Molecular Biology - Volume 35, Issue 4, April 2005, Pages 263-275
نویسندگان
Susan K. Fellner, Robert Rybczynski, Lawrence I. Gilbert,