Stimulation of trehalose efflux from cockroach (Periplaneta americana) fat body by hypertrehalosemic hormone is dependent on protein kinase C and calmodulin
| Autor: | D. Sun, Garcha K, J.E. Steele |
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| Rok vydání: | 2002 |
| Předmět: |
Male
Thapsigargin Phosphorylases Calmodulin Physiology Fat Body Biochemistry Diglycerides chemistry.chemical_compound Glycogen phosphorylase BAPTA Sphingosine Animals Periplaneta Enzyme Inhibitors Egtazic Acid Protein Kinase C Protein kinase C Chelating Agents biology Neuropeptides Trehalose General Medicine Trifluoperazine Enzyme Activation Cytosol chemistry Insect Science biology.protein Tetradecanoylphorbol Acetate Calcium Efflux |
| Zdroj: | Archives of Insect Biochemistry and Physiology. 50:41-51 |
| ISSN: | 1520-6327 0739-4462 |
| DOI: | 10.1002/arch.10028 |
| Popis: | Protein kinase C and calmodulin play key roles in cockroach fat body during activation of phosphorylase and trehalose efflux by HTH-II. The data support the view that an increase in cytosolic Ca2+ is prerequisite for enhanced activity of protein kinase C and calmodulin. Chelation of Ca2+ (i) with BAPTA blocks HTH-II-induced trehalose efflux from the fat body whereas thapsigargin, which raises [Ca2+]i to the same level as HTH-II, produces only a small, yet significant increase in trehalose efflux. Sphingosine, an inhibitor of protein kinase C, inhibits HTH-II-induced trehalose efflux in a concentration-dependent manner. Trehalose efflux is not activated by the protein kinase C activators OAG or PMA alone but in the presence of thapsigargin both agents increase trehalose efflux to a level comparable to that obtained with HTH-II. Thapsigargin has only a moderate activating effect on phosphorylase but in combination with OAG produces an activation indistinguishable from that provoked by HTH-II. Each of the structurally different calmodulin inhibitors, trifluoperazine, W-7, and calmidazolium, blocks completely the action of HTH-II on trehalose efflux, thus confirming the importance of calmodulin in HTH-II initiated trehalose efflux. |
| Databáze: | OpenAIRE |
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