Cytochemical Localization of Guanylate and Adenylate Cyclase in Photoreceptor Cells of the Fly

1995 ◽  
Vol 50 (9-10) ◽  
pp. 695-698 ◽  
Author(s):  
Ulrich Schraermeyer ◽  
Hennig Stieve ◽  
Michael Rack
Keyword(s):  
Spatial Distribution ◽  
Adenylate Cyclase ◽  
Guanylate Cyclase ◽  
Cyclic Nucleotides ◽  
Photoreceptor Cells ◽  
Cytochemical Localization ◽  
Calliphora Erythrocephala ◽  
Cytochemical Method ◽  
Enzyme Cascade

Abstract In photoreceptor cells of invertebrates light triggers an enzyme cascade in which the phos-phoinositide pathway is crucially involved. Likewise, there is growing evidence of an impor­ tant role of cyclic nucleotides, too. To localize these enzymes able to catalyze the formation of cGM P and cAMP, the spatial distribution of guanylate cyclase (EC 4.6.1.2) and adenylate cyclase (EC 4.6.1.1) was determined in photoreceptor cells of the fly. In photoreceptor cells of the blowfly (Calliphora erythrocephala), the electron dense reaction product of guanylate cyclase was found within the phototransducing region, the rhabdomeral microvilli and in the mitochondria. Staining was also observed throughout the cytoplasm of the microvilli. With the same cytochemical method, reaction product for adenylate cyclase was found on the tips of the photosensory membrane, and not in the cytoplasm of the rhabdomeral microvilli. The results presented here further argue for an important role of one or possibly two cyclic nucleotides in the photoreceptor cells, and possibly in the process of phototransduction of in­ vertebrates.

scholarly journals Cytochemical methods for the localization of adenylate cyclase. A review and evaluation of the efficacy of the procedures.

1983 ◽  
Vol 31 (1) ◽  
pp. 85-93 ◽  
Author(s):  
L S Cutler
Keyword(s):  
Adenylate Cyclase ◽  
Cyclic Nucleotides ◽  
Cell Biology ◽  
Enzyme System ◽  
Cyclic Adenosine Monophosphate ◽  
Adenosine Monophosphate ◽  
Cellular Functions ◽  
Cytochemical Localization ◽  
Biochemical Evaluation

The cytochemical procedures for localizing adenylate cyclase have been a source of controversy since their introduction. The importance of cyclic adenosine monophosphate (AMP), the product of adenylate cyclase's action on adenosine triphosphate (ATP), in cell biology is clear. Thus, the ability to localize this enzyme system reliably is an important tool in the study of various cellular functions. This report reviews the literature and presents a biochemical evaluation of the methods for localizing adenylate cyclase. The review and data presented serve to clarify many of the controversies surrounding this important cytochemical procedure. It is evident that although there are problems associated with localizing the enzyme, several valid procedures are currently available for the cytochemical localization of adenylate cyclase. In using these procedures, the effects of fixation and the capture agent on adenylate cyclase activity in the particular tissue being studied should be considered. Only repurified adenylyl imidodiphosphate [App(NH)p] should be used in the incubation medium. If care is taken, the use of these techniques can be of great value in the continued study of the role of cyclic nucleotides in cell biology.

Cytochemical localization of guanylate cyclase in photoreceptor cells of the mouse

1997 ◽  
Vol 235 (3) ◽  
pp. 176-179 ◽  
Author(s):  
Ulrich Schraermeyer ◽  
Peter Esser ◽  
Salvatore Grisanti ◽  
Michael Rack ◽  
Klaus Heimann
Keyword(s):  
Guanylate Cyclase ◽  
Photoreceptor Cells ◽  
Cytochemical Localization

Regulation of Melatonin Production by Pineal Photoreceptor Cells: Role of Cyclic Nucleotides in the Trout (Oncorhynchus mykiss)

1993 ◽  
Vol 61 (1) ◽  
pp. 332-339 ◽  
Author(s):  
Christelle Thibault ◽  
Jacky Falcón ◽  
Shelley S. Greenhouse ◽  
Christopher A. Lowery ◽  
William A. Gern ◽  
...  
Keyword(s):  
Oncorhynchus Mykiss ◽  
Cyclic Nucleotides ◽  
Photoreceptor Cells ◽  
Melatonin Production

scholarly journals The metabolism of cyclic nucleotides in the guinea-pig pancreas. Adenylate cyclase and guanylate cyclase

1980 ◽  
Vol 186 (2) ◽  
pp. 499-505 ◽  
Author(s):  
M Lemon ◽  
P Methven ◽  
K Bhoola
Keyword(s):  
Adenylate Cyclase ◽  
Guinea Pig ◽  
Guanylate Cyclase ◽  
Cyclic Nucleotides ◽  
Cyclase Activity ◽  
Dependent Manner ◽  
Guanylate Cyclase Activity ◽  
Triton X ◽  
Dose Dependent ◽  
Significant Activation

Adenylate cyclase from the guinea-pig pancreas was activated in a dose-dependent manner by both secretin and cholecystokinin-pancreozymin, but in contrast with results in other species the hormones were approximately equipotent. All other hormones and transmitter substances tested were without any effect on adenylate cyclase activity. Guanylate cyclase activity was shown to have both particulate and supernatant components in the guinea-pig pancreas. The particulate enzyme, but not the supernatant enzyme, was markedly activated by Triton X-100, and most of the induced activity was released into the supernatant. The supernatant enzyme was specifically Mn2+-dependent, but, even though Mn2+ was maximally effective at a concentration of 3 mM, activity could be raised further by increasing Ca2+ concentration. The particulate enzyme, by contrast, was relatively Mn2+-independent. Activity of the particulate guanylate cyclase was enhanced by phosphatidylserine. The supernatant enzyme displayed classical Michaelis-Menten kinetics, but the particulate enzyme deviated markedly from such kinetics. Under none of the conditions used was any significant activation of guanylate cyclase observed with any of the secretogen hormones or transmitter substances.

scholarly journals Regulation of ciliary adenylate cyclase by Ca2+ in Paramecium

1987 ◽  
Vol 246 (2) ◽  
pp. 337-345 ◽  
Author(s):  
M C Gustin ◽  
D L Nelson
Keyword(s):  
Cyclic Amp ◽  
Adenylate Cyclase ◽  
Guanylate Cyclase ◽  
Cyclic Nucleotides ◽  
Second Messengers ◽  
Active Agent ◽  
Ciliated Protozoan ◽  
Calmodulin Antagonists ◽  
Ciliary Membrane ◽  
Ca2 Channels

In the ciliated protozoan Paramecium, Ca2+ and cyclic nucleotides are believed to act as second messengers in the regulation of the ciliary beat. Ciliary adenylate cyclase was activated 20-30-fold (half-maximal at 0.8 microM) and inhibited by higher concentrations (10-20 microM) of free Ca2+ ion. Ca2+ activation was the result of an increase in Vmax., not a change in Km for ATP. The activation by Ca2+ was seen only with Mg2+ATP as substrate; with Mn2+ATP the basal adenylate cyclase activity was 10-20-fold above that with Mg2+ATP, and there was no further activation by Ca2+. The stimulation by Ca2+ of the enzyme in cilia and ciliary membranes was blocked by the calmodulin antagonists calmidazolium (half-inhibition at 5 microM), trifluoperazine (70 microM) and W-7 (50-100 microM). When ciliary membranes (which contained most of the ciliary adenylate cyclase) were prepared in the presence of Ca2+, their adenylate cyclase was insensitive to Ca2+ in the assay. However, the inclusion of EGTA in buffers used for fractionation of cilia resulted in full retention of Ca2+-sensitivity by the ciliary membrane adenylate cyclase. The membrane-active agent saponin specifically suppressed the Ca2+-dependent adenylate cyclase without inhibiting basal activity with Mg2+ATP or Mn2+ATP. The ciliary adenylate cyclase was shown to be distinct from the Ca2+-dependent guanylate cyclase; the two activities had different kinetic parameters and different responses to added calmodulin and calmodulin antagonists. Our results suggest that Ca2+ influx through the voltage-sensitive Ca2+ channels in the ciliary membrane may influence intraciliary cyclic AMP concentrations by regulating adenylate cyclase.

Actin and α-tubulin immuno-EM labelings reveal differences in intra versus interphotoreceptor matrix

1990 ◽  
Vol 48 (3) ◽  
pp. 466-467
Author(s):  
Matti Järvilehto ◽  
Riitta Harjula
Keyword(s):  
Compound Eye ◽  
Frozen Section ◽  
Smooth Muscle Actin ◽  
Photoreceptor Cells ◽  
Immune Serum ◽  
Cell Organelles ◽  
Calliphora Erythrocephala ◽  
Optical Axes ◽  
Interphotoreceptor Matrix ◽  
Similar Kind

The photoreceptor cells in the compound eyes of higher diptera are clustered in groups (ommatidia) of eight receptor cells. The cells from six adjacent ommatidia are organized into optical units, neuro-ommatia sharing the same visual field. In those ommatidia the optical axes of the photopigment containing structures (rhabdomeres) are parallel. The rhabdomeres of the photoreceptor cells are separated from each other by an interstitial i.e innerommatidial space (IOS). In the photoreceptor cell body, besides of the normal cell organelles, a cellular matrix is a structurally apparent component. Similar kind of reticular formation is also found in the IOS containing some unidentified filamentary substance, of which composition and functional significance for optical properties of vision is the aim of this report.The prefixed (2% PA + 0.2% GA in 0.1-n phosphate buffer, pH 7.4, for 1h), frozen section blocks of the compound eye of the blowfly (Calliphora erythrocephala) were prepared by immuno-cryo-techniques. The ultrathin cryosections were incubated with antibodies of monoclonal α-tubulin and polyclonal smooth muscle actin. Control labelings of excess of antigen, non-immune serum and non-present antibody were perforated.

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