Identification and characterization of developmentally regulated mRNP proteins of Dictyostelium discoideum

This study reports the identification and characterization of a cAMP-specific phosphodiesterase from the parasitic hemoflagellateTrypanosoma brucei. TbPDE2A is a class I phosphodiesterase. Its catalytic domain exhibits 30–40% sequence identity with those of all 11 mammalian phosphodiesterase (PDE) families, as well as withPDE2fromSaccharomyces cerevisiae,duncefromDrosophila melanogaster, andregAfromDictyostelium discoideum. The overall structure of TbPDE2A resembles that of human PDE11A in that its N-terminal region contains a single GAF domain. This domain is very similar to those of the mammalian PDE2, -5, -6, -10, and -11, where it constitutes a potential cGMP binding site. TbPDE2A can be expressed inS. cerevisiae, and it complements anS. cerevisiaePDE deletion strain. Recombinant TbPDE2A is specific for cAMP, with aKmof ∼2 μm. It is entirely resistant to the nonselective PDE inhibitor 3-isobutyl-1-methylxanthine, but it is sensitive to trequinsin, dipyridamole, sildenafil, and ethaverine with IC50values of 5.4, 5.9, 9.4, and 14.2 μm, respectively. All four compounds inhibit proliferation of bloodstream form trypanosomes in culture, indicating that TbPDE2A is an essential enzyme.

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Identification and Characterization of Neuron-Specific and Developmentally Regulated Gene Transcripts in the Chick Embryo Spinal Cord

Journal of Neurochemistry ◽

10.1111/j.1471-4159.1986.tb13041.x ◽

1986 ◽

Vol 46 (3) ◽

pp. 787-793 ◽

Cited By ~ 11

Author(s):

John G. Dickson ◽

Howard M. Prentice ◽

James G. Kenimer ◽

Frank S. Walsh

Keyword(s):

Spinal Cord ◽

Chick Embryo ◽

Developmentally Regulated ◽

Gene Transcripts ◽

Identification And Characterization

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Identification and Characterization of a Developmentally Regulated Protein, EshA, Required for Sporogenic Hyphal Branches in Streptomyces griseus

Journal of Bacteriology ◽

10.1128/jb.183.10.3004-3015.2001 ◽

2001 ◽

Vol 183 (10) ◽

pp. 3004-3015 ◽

Cited By ~ 14

Author(s):

Jangyul Kwak ◽

Lee Ann McCue ◽

Kristen Trczianka ◽

Kathleen E. Kendrick

Keyword(s):

Cyclic Nucleotide ◽

Streptomyces Griseus ◽

Branch Points ◽

Developmentally Regulated ◽

Two Dimensional Gel Electrophoresis ◽

Spore Viability ◽

Specific Proteins ◽

Identification And Characterization ◽

Spore Maturation

ABSTRACT To identify sporulation-specific proteins that might serve as targets of developmental regulatory factors inStreptomyces, we examined total proteins ofStreptomyces griseus by two-dimensional gel electrophoresis. Among five proteins that were present at high levels during sporulation but absent from vegetative cells, two of the proteins, P3 and P4, were absent from developmental mutants that undergo aberrant morphogenesis. The deduced amino acid sequence of the gene that encodes P3 (EshA) showed extensive similarity to proteins from mycobacteria and a cyanobacterium, Synechococcus, that are abundant during nutritional stress but whose functions are unknown. Uniquely among these proteins, EshA contains a cyclic nucleotide-binding domain, suggesting that the activity of EshA may be modulated by a cyclic nucleotide. The eshA gene was strongly expressed from a single transcription start site only during sporulation, and accumulation of the eshA transcript depended on a developmental gene, bldA. During submerged sporulation, a null mutant strain that produced no EshA could not extend sporogenic hyphae from new branch points but instead accelerated septation and spore maturation at the preexisting vegetative filaments. These results indicated that EshA is required for the growth of sporogenic hyphae and localization of septation and spore maturation but not for spore viability.

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