Biomaterial Database

Involvement of RSK phosphorylation in PTTH-stimulated ecdysone secretion in prothoracic glands of the silkworm, Bombyx mori. 2021

S-H Gu, and C-H Chen

Department of Biology, National Museum of Natural Science, Taichung, Taiwan.

It is well known that phosphorylation of extracellular signal-regulated kinase (ERK) is involved in prothoracicotropic hormone (PTTH)-stimulated ecdysteroidogenesis in insect prothoracic glands (PGs). In the present study, we further investigated the downstream signalling pathways. Our results showed that PTTH stimulated p90 ribosomal S6 kinase (RSK) phosphorylation at Thr573 in Bombyx mori PGs both in vitro and in vivo. The in vitro PTTH stimulation was stage- and dose-dependent. The absence of Ca2+ reduced PTTH-stimulated RSK phosphorylation. Stimulation of RSK phosphorylation was also observed after treatment with either A23187 or thapsigargin. A phospholipase C (PLC) inhibitor, U73122, blocked PTTH-stimulated RSK phosphorylation. These results indicate the involvement of Ca2+ and PLC. Treatment with diphenylene iodonium (DPI), a mitochondrial oxidative phosphorylation inhibitor, blocked PTTH-regulated RSK phosphorylation, indicating its redox regulation. A mitogen-activated protein kinase (MAPK)/ERK kinase (MEK) inhibitor, U0126, but not a phosphatidylinositol 3-kinase (PI3K) inhibitor, LY294002, decreased PTTH-stimulated RSK phosphorylation, indicating that ERK is an upstream signalling. A protein kinase C (PKC) inhibitor, chelerythrine C, inhibited PTTH-stimulated RSK phosphorylation, and a PKC activator, phorbol 12-myristate acetate (PMA) stimulated RSK phosphorylation, indicating the involvement of PKC. BI-D1870, a specific RSK inhibitor, partly prevented PTTH-stimulated RSK phosphorylation and significantly inhibited PTTH-stimulated ecdysteroid secretion, indicating that PTTH-stimulated RSK phosphorylation is involved in ecdysteroidogenesis. Taken together, these data indicate that PTTH activates RSK phosphorylation which plays important roles in PTTH-stimulated ecdysteroidogenesis.

UI	MeSH Term	Description	Entries
D007301	Insect Hormones	Hormones secreted by insects. They influence their growth and development. Also synthetic substances that act like insect hormones.	Insect Hormone,Hormone, Insect,Hormones, Insect
D007814	Larva	Wormlike or grublike stage, following the egg in the life cycle of insects, worms, and other metamorphosing animals.	Maggots,Tadpoles,Larvae,Maggot,Tadpole
D010766	Phosphorylation	The introduction of a phosphoryl group into a compound through the formation of an ester bond between the compound and a phosphorus moiety.	Phosphorylations
D004440	Ecdysone	A steroid hormone that regulates the processes of MOLTING or ecdysis in insects.	Molting Hormone
D000081082	Phosphoinositide-3 Kinase Inhibitors	Agents that inhibit PHOSPHOINOSITIDE-3 KINASE activity.	Phosphoinositide-3 Kinase Inhibitor,Inhibitor, Phosphoinositide-3 Kinase,Inhibitors, Phosphoinositide-3 Kinase,Kinase Inhibitor, Phosphoinositide-3,Kinase Inhibitors, Phosphoinositide-3,Phosphoinositide 3 Kinase Inhibitor,Phosphoinositide 3 Kinase Inhibitors
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D012831	Bombyx	A genus of silkworm MOTHS in the family Bombycidae of the order LEPIDOPTERA. The family contains a single species, Bombyx mori from the Greek for silkworm + mulberry tree (on which it feeds). A native of Asia, it is sometimes reared in this country. It has long been raised for its SILK and after centuries of domestication it probably does not exist in nature. It is used extensively in experimental GENETICS. (From Borror et al., An Introduction to the Study of Insects, 4th ed, p519)	Bombyx mori,Silkmoths,Silkworms,Silkmoth,Silkworm,Bombyx morus,Bombyxs,mori, Bombyx
D048049	Extracellular Signal-Regulated MAP Kinases	A mitogen-activated protein kinase subfamily that is widely expressed and plays a role in regulation of MEIOSIS; MITOSIS; and post mitotic functions in differentiated cells. The extracellular signal regulated MAP kinases are regulated by a broad variety of CELL SURFACE RECEPTORS and can be activated by certain CARCINOGENS.	ERK MAP Kinase,ERK MAP Kinases,Extracellular Signal-Regulated Kinase,Extracellular Signal-Regulated Kinases,Extracellular Signal-Regulated MAP Kinase,MAP Kinases, Extracellular Signal-Regulated,Extracellular Signal Regulated Kinase,Extracellular Signal Regulated Kinases,Extracellular Signal Regulated MAP Kinase,Extracellular Signal Regulated MAP Kinases,Kinase, ERK MAP,Kinase, Extracellular Signal-Regulated,Kinases, Extracellular Signal-Regulated,MAP Kinase, ERK,MAP Kinases, Extracellular Signal Regulated,Signal-Regulated Kinase, Extracellular
D026461	Ecdysteroids	Steroids that bring about MOLTING or ecdysis in insects. Ecdysteroids include the endogenous insect hormones (ECDYSONE and ECDYSTERONE) and the insect-molting hormones found in plants, the phytoecdysteroids. Phytoecdysteroids are natural insecticides.	Ecdysteroid
D038744	Ribosomal Protein S6 Kinases, 90-kDa	A family of ribosomal protein S6 kinases that are structurally distinguished from RIBOSOMAL PROTEIN S6 KINASES, 70-KDA by their apparent molecular size and the fact they contain two functional kinase domains. Although considered RIBOSOMAL PROTEIN S6 KINASES, members of this family are activated via the MAP KINASE SIGNALING SYSTEM and have been shown to act on a diverse array of substrates that are involved in cellular regulation such as RIBOSOMAL PROTEIN S6 and CAMP RESPONSE ELEMENT-BINDING PROTEIN.	MAP-Kinase-Activated Kinase 1,MAP-Kinase-Activated Protein Kinase 1,MAPKAP Kinase-1,MAPKAP-K1,MAPKAPK1,Ribosomal Protein S6 Kinase, 90-kDa,p90 Ribosomal S6 Kinase,p90(rsk),pp90(rsk),MAP Kinase Activated Kinase 1,MAP Kinase Activated Protein Kinase 1,MAPKAP Kinase 1,Ribosomal Protein S6 Kinase, 90 kDa,Ribosomal Protein S6 Kinases, 90 kDa