scholarly journals ForC, a novel type of formin family protein lacking an FH1 domain, is involved in multicellular development in Dictyostelium discoideum

2003 ◽  
Vol 116 (4) ◽  
pp. 711-723 ◽  
Author(s):  
C. Kitayama
Keyword(s):  
Dictyostelium Discoideum ◽  
Multicellular Development ◽  
Family Protein

scholarly journals The distribution of myosin II in Dictyostelium discoideum slug cells.

1991 ◽  
Vol 115 (5) ◽  
pp. 1267-1274 ◽  
Author(s):  
S Eliott ◽  
P H Vardy ◽  
K L Williams
Keyword(s):  
Cell Motility ◽  
Dictyostelium Discoideum ◽  
Immunofluorescence Microscopy ◽  
Molecular Genetic ◽  
Myosin Ii ◽  
Three Dimensional ◽  
Homogeneous Distribution ◽  
Multicellular Development ◽  
Insight Into

While the role of myosin II in muscle contraction has been well characterized, less is known about the role of myosin II in non-muscle cells. Recent molecular genetic experiments on Dictyostelium discoideum show that myosin II is necessary for cytokinesis and multicellular development. Here we use immunofluorescence microscopy with monoclonal and polyclonal antimyosin antibodies to visualize myosin II in cells of the multicellular D. discoideum slug. A subpopulation of peripheral and anterior cells label brightly with antimyosin II antibodies, and many of these cells display a polarized intracellular distribution of myosin II. Other cells in the slug label less brightly and their cytoplasm displays a more homogeneous distribution of myosin II. These results provide insight into cell motility within a three-dimensional tissue and they are discussed in relation to the possible roles of myosin II in multicellular development.

scholarly journals Wild Dictyostelium discoideum social amoebae show plastic responses to the presence of nonrelatives during multicellular development

2020 ◽  
Vol 10 (3) ◽  
pp. 1119-1134
Author(s):  
Suegene Noh ◽  
Lauren Christopher ◽  
Joan E. Strassmann ◽  
David C. Queller
Keyword(s):  
Dictyostelium Discoideum ◽  
Multicellular Development ◽  
Plastic Responses ◽  
Social Amoebae

scholarly journals CbfA, the C-Module DNA-Binding Factor, Plays an Essential Role in the Initiation of Dictyostelium discoideum Development

2004 ◽  
Vol 3 (5) ◽  
pp. 1349-1358 ◽  
Author(s):  
Thomas Winckler ◽  
Negin Iranfar ◽  
Peter Beck ◽  
Ingo Jennes ◽  
Oliver Siol ◽  
...  
Keyword(s):  
Dna Binding ◽  
Cell Density ◽  
Dictyostelium Discoideum ◽  
Ectopic Expression ◽  
Development Program ◽  
Cell Physiology ◽  
Dependent Manner ◽  
Wild Type ◽  
Gene Encoding ◽  
Multicellular Development

ABSTRACT We recently isolated from Dictyostelium discoideum cells a DNA-binding protein, CbfA, that interacts in vitro with a regulatory element in retrotransposon TRE5-A. We have generated a mutant strain that expresses CbfA at <5% of the wild-type level to characterize the consequences for D. discoideum cell physiology. We found that the multicellular development program leading to fruiting body formation is highly compromised in the mutant. The cells cannot aggregate and stay as a monolayer almost indefinitely. The cells respond properly to prestarvation conditions by expressing discoidin in a cell density-dependent manner. A genomewide microarray-assisted expression analysis combined with Northern blot analyses revealed a failure of CbfA-depleted cells to induce the gene encoding aggregation-specific adenylyl cyclase ACA and other genes required for cyclic AMP (cAMP) signal relay, which is necessary for aggregation and subsequent multicellular development. However, the cbfA mutant aggregated efficiently when mixed with as few as 5% wild-type cells. Moreover, pulsing cbfA mutant cells developing in suspension with nanomolar levels of cAMP resulted in induction of acaA and other early developmental genes. Although the response was less efficient and slower than in wild-type cells, it showed that cells depleted of CbfA are able to initiate development if given exogenous cAMP signals. Ectopic expression of the gene encoding the catalytic subunit of protein kinase A restored multicellular development of the mutant. We conclude that sensing of cell density and starvation are independent of CbfA, whereas CbfA is essential for the pattern of gene expression which establishes the genetic network leading to aggregation and multicellular development of D. discoideum.

scholarly journals Dynacortin, a Genetic Link between Equatorial Contractility and Global Shape Control Discovered by Library Complementation of a Dictyostelium discoideum Cytokinesis Mutant

2000 ◽  
Vol 150 (4) ◽  
pp. 823-838 ◽  
Author(s):  
Douglas N. Robinson ◽  
James A. Spudich
Keyword(s):  
Dictyostelium Discoideum ◽  
Shape Control ◽  
Myosin Ii ◽  
Genetic Interactions ◽  
Cell Cortex ◽  
Cleavage Furrow ◽  
Family Protein ◽  
Globally Distributed ◽  
Suppression Strategy ◽  
Novel Protein

We have developed a system for performing interaction genetics in Dictyostelium discoideum that uses a cDNA library complementation/multicopy suppression strategy. Chemically mutagenized cells were screened for cytokinesis-deficient mutants and one mutant was subjected to library complementation. Isolates of four different genes were recovered as modifiers of this strain's cytokinesis defect. These include the cleavage furrow protein cortexillin I, a novel protein we named dynacortin, an ezrin-radixin-moesin-family protein, and coronin. The cortexillin I locus and transcript were found to be disrupted in the strain, identifying it as the affected gene. Dynacortin is localized partly to the cell cortex and becomes enriched in protrusive regions, a localization pattern that is similar to coronin and partly dependent on RacE. During cytokinesis, dynacortin is found in the cortex and is somewhat enriched at the poles. Furthermore, it appears to be reduced in the cleavage furrow. The genetic interactions and the cellular distributions of the proteins suggest a hypothesis for cytokinesis in which the contraction of the medial ring is a function of spatially restricted cortexillin I and myosin II and globally distributed dynacortin, coronin, and RacE.

scholarly journals Mitochondrial regulation in Dictyostelium discoideum

2018 ◽  
Author(s):  
Mehak Rafiq
Keyword(s):  
Dictyostelium Discoideum ◽  
Serine Proteases ◽  
Model Organism ◽  
Complex Life Cycle ◽  
Transcriptional Networks ◽  
Multicellular Development ◽  
Mitochondrial Regulation ◽  
Rhomboid Proteases ◽  
The Social ◽  
Membrane Bound

Proteolysis is increasingly documented as a method of regulation of mitochondrial function. Our studies of rhomboidfamily proteins’ roles in organelles show that this is also the case in the social amoeba Dictyostelium discoideum, in which four of these membrane-bound, evolutionarily ubiquitous, serine proteases are found. Rhomboid proteases act on disparate substrates in different organisms so far studied, but their mode of action is conserved: their location in the membrane means that their membrane-tethered substrates can act in signalling upon release, or be activated, by rhomboid-mediated cleavage. Among eukaryotic rhomboids is the mitochondrial protease ‘PARL’, which ensures the maintenance of the structural and functional integrity of mitochondria and plastids, but we have found that other Dictyostelium rhomboids also affect the organelle. Studying the development and behaviour of Dictyostelium, a microbial model organism with a complex life cycle that includes uni- and multicellular stages, allowed investigation of the role of rhomboids in unicellular vegetative growth, multicellular development and sporulation, phagocytosis, and response to the environment. We found that two rhomboid-null mutants gave rise to changes in development, rhmA altering the response to chemoattractants and demonstrating decreased motility in general, whereas rhmB null cells had slower growth rates with decreased response to folic acid. RhmA, although located in the contractile vacuole, affects the ultrastructure of mitochondria, and RhmB-GFP fusions protein was localised to the mitochondrion. qPCR analysis revealed RhmA and RhmB transcript levels peaking during the multicellular growth phase and transcriptional networks suggest the Dictyostelium rhmA is regulated along with the orthologues of Saccharomyces cerevisiae mitochondrial rhomboid substrates.

DdAlix, an Alix/AIP1 homolog in Dictyostelium discoideum, is required for multicellular development under low Ca2+ conditions

Gene ◽  
2004 ◽  
Vol 337 ◽  
pp. 131-139 ◽  
Author(s):  
Susumu Ohkouchi ◽  
Medhat S El-Halawany ◽  
Fumika Aruga ◽  
Hideki Shibata ◽  
Kiyotaka Hitomi ◽  
...  
Keyword(s):  
Dictyostelium Discoideum ◽  
Multicellular Development

scholarly journals Structure of two developmentally regulated Dictyostelium discoideum ubiquitin genes.

1987 ◽  
Vol 7 (6) ◽  
pp. 2097-2103 ◽  
Author(s):  
R Giorda ◽  
H L Ennis
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Amino Acid Sequence ◽  
Dictyostelium Discoideum ◽  
Cdna Clone ◽  
Tandem Repeats ◽  
Computer Search ◽  
Developmentally Regulated ◽  
Genomic Libraries ◽  
Multicellular Development

A previously isolated cDNA clone, pLK229, that is specific for mRNA developmentally expressed during Dictyostelium discoideum spore germination and multicellular development, was used to screen two genomic libraries. Two genomic sequences homologous to pLK229 were isolated and sequenced. Genomic clone p229 is identical to the cDNA clone pLK229 and codes for a polypeptide of 381 amino acids. This polypeptide is composed of five tandem repeats of the same 76-amino-acid sequence. Clone lambda 229 codes for a protein of 229 amino acids, containing three tandem repeats of the identical 76-amino-acid sequence. A computer search for homology to known proteins revealed that the 76-amino-acid repeat was identical to human and bovine ubiquitin except for two amino acid differences.

scholarly journals Arrestins function in cAR1 GPCR-mediated signaling and cAR1 internalization in the development of Dictyostelium discoideum

2014 ◽  
Vol 25 (20) ◽  
pp. 3210-3221 ◽  
Author(s):  
Xiumei Cao ◽  
Jianshe Yan ◽  
Shi Shu ◽  
Joseph A. Brzostowski ◽  
Tian Jin
Keyword(s):  
Dictyostelium Discoideum ◽  
Protein C ◽  
Wild Type ◽  
Multicellular Development ◽  
Membrane Recruitment ◽  
Camp Receptor ◽  
Erk2 Activation ◽  
G Protein Coupled ◽  
Camp Stimulation ◽  
Signaling Circuit

Oscillation of chemical signals is a common biological phenomenon, but its regulation is poorly understood. At the aggregation stage of Dictyostelium discoideum development, the chemoattractant cAMP is synthesized and released at 6-min intervals, directing cell migration. Although the G protein–coupled cAMP receptor cAR1 and ERK2 are both implicated in regulating the oscillation, the signaling circuit remains unknown. Here we report that D. discoideum arrestins regulate the frequency of cAMP oscillation and may link cAR1 signaling to oscillatory ERK2 activity. Cells lacking arrestins (adcB−C−) display cAMP oscillations during the aggregation stage that are twice as frequent as for wild- type cells. The adcB−C− cells also have a shorter period of transient ERK2 activity and precociously reactivate ERK2 in response to cAMP stimulation. We show that arrestin domain–containing protein C (AdcC) associates with ERK2 and that activation of cAR1 promotes the transient membrane recruitment of AdcC and interaction with cAR1, indicating that arrestins function in cAR1-controlled periodic ERK2 activation and oscillatory cAMP signaling in the aggregation stage of D. discoideum development. In addition, ligand-induced cAR1 internalization is compromised in adcB−C− cells, suggesting that arrestins are involved in elimination of high-affinity cAR1 receptors from cell surface after the aggregation stage of multicellular development.

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