EurekaMag.com logo
+ Translate

Regulation of glycogen phosphorylase in fat body of cecropia silk moth hyalophora cecropia pupae


, : Regulation of glycogen phosphorylase in fat body of cecropia silk moth hyalophora cecropia pupae. Journal of Comparative Physiology B Biochemical Systemic & Environmental Physiology 131(4): 321-332

Glycogen phosphorylase of pupal fat body of the silkmoth, H. cecropia, and its activation by different stimuli were studied. Spectrophotometric assay in the direction of glycogenolysis, used in the most of the experiments, indicated higher amounts of phosphorylase a than assay by release of Pi from glucose-1-phosphate; both assays estimated changes in proportion of phosphorylase a equally. the Km s for Pi were estimated as 5 mM for phosphorylase a in the absence of AMP and 18 mM for phosphorylase b with 2 mM AMP. When diapausing pupae were hold at 4.degree. C, fat body phosphorylase was quickly activated by conversion to the a form up to .apprx. 50% of the total, and then declined again after 30 days, when glycerol had accumulated in the hemolymph. Cold activatio in vivo was quickly reversed at 25.degree. C. Removal of the brain did not prevent cold activation. After storage at 15.degree. C, sensitivity to cold activation was diminished. Locusts [Locusta migratoria] and crickets [Acheta domesticus] also showed activation of phosphorylase after chilling. Exposure of fat body to air, transfer to Ringer solution, or physical agitation, caused activation of phosphorylase which is classed as shock activation. After .apprx. 1 h incubation in Ringer at 25.degree. C, this effect reversed spontaneously. Activation also occurred in fat body in vitro after transfer to 0.degree. C (cold activation), and was reversed at 25.degree. C. The previously reported inhibition of activation by glycerol could not be consistently reproduced. In fat body homogenates, phosphorylase b was converted to phosphorylase a by incubation with ATP and Mg2+, which indicates activity of phosphorylase kinase. In preparations treated with Sephadex G-25 and then incubated, the reverse conversion took place, which was inhibited by fluoride, and indicates activity of phosphorylase phosphatase. Cyclic AMP added to fat body in vitro, or theophylline either in vivo or in vitro, stimulated the activation of phosphorylase. In fat body in vitro, shock activation was paralleled by elevation of tissue cyclic AMP, whereas cold activation was not. Cyclic GMP did not stimulate activation, and showed no significant changes in tissue levels. Consequently, the conversion of silkmoth pupal fat body phosphorylase b to phosphorylase a can be stimulated by a shock-initiated mechanism involving cyclic AMP and a distinct cold-initiated mechanism independent of cyclic AMP.

(PDF 0-2 workdays service)

Accession: 006288174

Submit PDF Full Text: Here


Submit PDF Full Text

No spam - Every submission is manually reviewed

Due to poor quality, we do not accept files from Researchgate

Submitted PDF Full Texts will always be free for everyone
(We only charge for PDFs that we need to acquire)

Select a PDF file:
Close
Close

Related references

Faye I.; Wyatt G.R., 1980: The synthesis of anti bacterial proteins in isolated fat body from cecropia hyalophora cecropia silk moth pupae. Experientia (Basel) 36(11): 1325-1326

Shirk P.D.; Bhaskaran G.; Roller H., 1980: The transfer of juvenile hormone from male to female during mating in the cecropia silk moth hyalophora cecropia. Experientia (Basel) 36(6): 682-683

Ziegler, R.; Ashida, M.; Fallon, A.M.; Wimer, L.T.; Wyatt, S.S.; Wyatt, G.R., 1979: Regulation of glycogen phosphorylase in fat body of cecropia silkmoth pupae. The major glycogen reserves of insects are located in the fat-body, a dispersed internal organ responsible for storage and metabolism of lipids, carbohydrates and proteins. The stored glycogen varies greatly in amount, and can be mobilised into th...

Filburn, C.R.; Karn, J.; Wyatt, G.R., 1977: Cyclic nucleotide phospho di esterases ec 3.1.4.17 of hyalophora cecropia silk moth fat body. Two soluble forms of 3':5'-cyclic-nucleotide phosphodiesterase (3':5'-cyclic-nucleotide 5'-nucleotidohydrolase, EC 3.1.4.17) were found in the larval fat body of the silkmoth H. cecropia. These differ in elution profile on...

Hultmark, D.E.gstrom, A1; Bennich, H1; Kapur, R1; Boman, H., 1982: Insect immunity: isolation and structure of cecropin D and four minor antibacterial components from Cecropia pupae Hyalophora cecropia. European journal of biochemistry 127(1): 207-217

Hultmark D.; Engstrom A.; Bennich H.; Kapur R.; Boman H.G., 1982: Insect immunity isolation and structure of cecropin d and 4 minor anti bacterial components from cecropia hyalophora cecropia pupae. LMW antibacterial proteins were investigated from the Cecropia moth, H. cecropia. In addition to the previously described cecropins A and B, 5 new antibacterial proteins were discovered, the cecropins C, D, E and F, and the factor G. A scheme for...

Pecina, P., 1982: The silk moth Hyalophora cecropia.. Ziva, 305: 190

Patel N.G.; Schneiderman H.A., 1969: The effects of perfusion on the synthesis and release of blood proteins by diapausing pupae of the cecropia silkworm hyalophora cecropia inst acrylamide gel electrophoresis densitometry. Journal of Insect Physiology 15(4): 643-660

Pollack S.B.; Telfer W.H., 1969: Rna in cecropia moth ovaries sites of synthesis transport and storage hyalophora cecropia. Journal of Experimental Zoology 17(1): 1-24

Mandelbaum I., 1980: Inter cellular bridges and the fusome in the germ cells of the cecropia moth hyalophora cecropia. Intercellular bridge development was compared in Cecropia by transmission electron microscopy in the germ cells of males and females. Bridge formation begins in the 4th instar, and the spindle remnants in newly formed bridges are replaced at this...