Cytokinin oxidase from Zea mays: purification, cDNA cloning and expression in moss protoplasts

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New Markers in Anopheles gambiae Salivary Glands After Plasmodium berghei Infection.

Abstract In malaria, mosquito saliva and salivary glands play central roles in the multi-faceted interactions that occur among the parasite, its vector, and its host. Analyzing the processes involved in the survival and maintenance of the Plasmodium parasite in mosquito organs, and in its transmission into vertebrate hosts, may lead to the identification of new molecular targets for parasite control. We used comparative two-dimensional gel polyacrylamide electrophoresis (2D-PAGE), surface-enhanced laser desorption/ionization time-of-flight mass spectrometry (SELDI-TOF-MS), and high-performance liquid chromatography (HPLC), followed by Edman sequencing, to study saliva and salivary gland samples from Anopheles gambiae mosquitoes infected or not with Plasmodium berghei. Quantitative 2D-PAGE profile analysis showed that the intensities of seven spots were affected by the presence of the parasite in the salivary glands. Most of the proteins identified possessed a signal peptide. SELDI-TOF-MS revealed 32 proteins/peptides whose peak intensities differed between the Plasmodium-infected and non-infected control groups. Quantitative comparison of HPLC profiles of low-molecular-weight components from salivary gland extracts revealed several peptides and proteins with levels that were modulated by parasite infection. The results of these complementary approaches suggest that the infection of female A. gambiae mosquitoes by P. berghei alters the production levels of several salivary gland proteins and peptides, some of which (e.g., protein cE5, B3VDI9_ANOGA, and AGAP008216-PA) are known or predicted to be secreted in saliva and involved in blood feeding

Identification of a common domain in calmodulin-activated eukaryotic and bacterial adenylate cyclases

International audienceBordetella pertussis and Bacillus anthracis, two taxonomically distinct bacteria, secrete adenylate cyclase toxins that are activated by the eukaryotic protein calmodulin. The two enzymes contain a well- conserved stretch of 24 amino acid residues [Escuyer et al. (1988) Gene 71, 293-298]. Antibodies have been obtained against two synthetic heptadecapeptides, covering part of the conserved sequences. The anti-peptide antibodies specifically reacted in Western blots with the rat brain adenylate cyclase as well as with the two bacterial enzymes. Anti-rat brain adenylate cyclase serum contained antibodies that were retained by the immobilized peptides, and the affinity-purified antibodies yielded the same recognition pattern of the eukaryotic enzyme as did the unfractionated serum. These results indicate that the eukaryotic adenylate cyclase contains an epitope closely related to that specified by the conserved bacterial sequence. The synthetic peptides and the bacterial adenylate cyclases appeared to compete for ATP (KD of the ATP-peptide complex ca. 0.2 mM), suggesting that the conserved sequence may be part of the substrate binding site in these two enzymes