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Trypanosoma cruzi adenylyl cyclases are encoded by a large polymorphic gene family. Although several genes have been identified in this parasite, little is known about the properties and regulation of these enzymes. Here we report the cloning and characterization of TczAC, a novel member of T. cruzi adenylyl cyclase family. The TczAC gene is expressed in(More)
Molecular properties of Neurospora soluble protein kinase and cyclic AMP binding activities have been determined. Cyclic AMP-dependent Peak I kinase activity with a molecular weight of 118 000 is composed of two subunits, catalytic and regulatory, having molecular weights of 55 000 and 57 000, respectively. Cyclic AMP-independent Peak II kinase activity has(More)
Phorbol ester binding was studied in protein kinase C-containing extracts obtained from Trypanosoma cruzi epimastigote forms. Specific 12-O-tetradecanoyl phorbol 13-acetate, [3H]PMA, or 12,13-O-dibutyryl phorbol, [3H]PDBu, binding activities, determined in T. cruzi epimastigote membranes, were dependent on ester concentration with a Kd of 9x10(-8) M and(More)
Trypanosoma cruzi, a protozoan responsible for the American trypanosomiasis (Chagas disease), multiplies and differentiates in the gut of triatomine insect vectors. The effects of hemoglobin and synthetic peptides carrying alpha D-globin fragments on both the growth and the transformation of T. cruzi epimastigotes (noninfective) into metacyclic(More)
A new member of the ras gene family was characterized from Neurospora crassa cDNA libraries. The clone designated NC-ras codes for a polypeptide containing 213 amino acids (Mr 24,000). This polypeptide is 84% homologous to the H-ras-1 domain comprising the first 80 amino acids and 60% homologous to the next 84 residues. The NC-ras polypeptide contains all(More)
Adenylate cyclase, the enzyme responsible for cyclic adenylate synthesis has been found in membrane fractions of animal cells (l-4). This enzyme system is stimulated by several hormones, showing a wide range of specificity. The occurrence of a similar enzyme activity has been also demonstrated in Escherichia coli and Bacillus liquejaciens (5-7)) but in(More)
Activation of cyclic AMP phosphodiesterase I by brain or Neurospora calmodulin was studied. The stimulation required micromolar concentrations of Ca2+, and it was observed at cyclic AMP concentrations between 0.1 and 500 microM. Activation was blocked by EDTA and some neuroleptic drugs such as chlorpromazine and fluphenazine. These drugs inhibit the(More)
The role of cyclic adenosine 3', 5'-monophosphate (cyclic AMP) in the control of the Neurospora asexual life cycle was studied. Endogenous cyclic AMP levels were 10 to 20 times higher in strains having the wild-type cr-1 allele than in those carrying the mutated allele. In a wild-type strain these levels remained constant throughtout the entire growth(More)
A peptide from hindguts of the Triatoma hematophagous Chagas insect vector activates adenylyl cyclase activity in Trypanosoma cruzi epimastigote membranes and stimulates the in vitro differentiation of epimastigotes to metacyclic trypomastigotes. Hindguts were obtained from insects fed 2 days earlier with chicken blood. Purification was performed by gel(More)