Protein kinase A and C are "Gatekeepers" of capacitative Ca2+ entry in the prothoracic gland cells of the silkworm, Bombyx mori.
Application of protein kinases A and C inhibitors to the prothoracic glands cells of the silkworm, Bombyx mori, resulted in slow and gradual increases in intracellular Ca(2+) ([Ca(2+)](i)). Pharmacological manipulation of the Ca(2+) signalling cascades in the prothoracic gland cells of B. mori suggests that these increases of [Ca(2+)](i) are mediated neither by voltage-gated Ca(2+) channels nor by intracellular Ca(2+) stores. Rather they result from slow Ca(2+) leak from plasma membrane Ca(2+) channels that are sensitive to agents that inhibit capacitative Ca(2+) entry and are abolished in the absence of extracellular Ca(2+). Okadaic acid, an inhibitor of PP1 and PP2A phosphatases, blocked the increase in [Ca(2+)](i) produced by the inhibitors of protein kinase A and C. The combined results indicate that the capacitative Ca(2+) entry channels in prothoracic gland cells of B. mori are probably modulated by protein kinases A and C.
Dedos
Skarlatos G
SG
Saxon Academy of Sciences at Leipzig, Department of Neurohormones, Erbertstr. 1, PF 100322, 07703 Jena, Germany. sd323@cam.ac.uk
Kaltofen
Sabine
S
Birkenbeil
Heiner
H
D000704:Analysis of Variance; D000818:Animals; D012831:Bombyx / Q000378:metabolism* / Q000502:physiology; D002118:Calcium / Q000378:metabolism*; D017868:Cyclic AMP-Dependent Protein Kinases / Q000378:metabolism*; D003592:Cytophotometry; D005088:Exocrine Glands / Q000378:metabolism*; D007814:Larva / Q000378:metabolism; D011493:Protein Kinase C / Q000378:metabolism*; D015398:Signal Transduction / Q000502:physiology*; D013997:Time Factors
D017868:Cyclic AMP-Dependent Protein Kinases; D011493:Protein Kinase C; D002118:Calcium