1
|
Kawabe Y, Schaap P. Development of the dictyostelid Polysphondylium violaceum does not require secreted cAMP. Biol Open 2023; 12:286712. [PMID: 36688866 PMCID: PMC9922732 DOI: 10.1242/bio.059728] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2022] [Accepted: 01/12/2023] [Indexed: 01/24/2023] Open
Abstract
Group 4 Dictyostelia, like Dictyostelium discoideum, self-organize into aggregates and fruiting bodies using propagating waves of the chemoattractant cAMP, which are produced by a network containing the adenylate cyclase AcaA, cAMP receptors (Cars) and the extracellular cAMP phosphodiesterase PdsA. Additionally, AcaA and the adenylate cyclases AcrA and AcgA produce secreted cAMP for induction of aggregative and prespore gene expression and intracellular cAMP for PKA activation, with PKA triggering initiation of development and spore and stalk maturation. Non-group 4 species also use secreted cAMP to coordinate post-aggregative morphogenesis and prespore induction but use other attractants to aggregate. To understand how cAMP's role in aggregation evolved, we deleted the acaA, carA and pdsA genes of Polysphondylium violaceum, a sister species to group 4. acaA- fruiting bodies had thinner stalks but otherwise developed normally. Deletion of acrA, which was similarly expressed as acaA, reduced aggregation centre initiation and, as also occurred after D. discoideum acrA deletion, caused spore instability. Double acaA-acrA- mutants failed to form stable aggregates, a defect that was overcome by exposure to the PKA agonist 8Br-cAMP, and therefore likely due to reduced intracellular cAMP. The carA- and pdsA- mutants showed normal aggregation and fruiting body development. Together, the data showed that P. violaceum development does not critically require secreted cAMP, while roles of intracellular cAMP in initiation of development and spore maturation are conserved. Apparently, cell-cell communication underwent major taxon-group specific innovation in Dictyostelia.
Collapse
Affiliation(s)
- Yoshinori Kawabe
- School of Life Sciences, Molecular, Cell and Developmental Biology, University of Dundee, Dundee DD15EH, UK
| | - Pauline Schaap
- School of Life Sciences, Molecular, Cell and Developmental Biology, University of Dundee, Dundee DD15EH, UK,Author for correspondence ()
| |
Collapse
|
2
|
Kawabe Y, Morio T, James JL, Prescott AR, Tanaka Y, Schaap P. Activated cAMP receptors switch encystation into sporulation. Proc Natl Acad Sci U S A 2009; 106:7089-94. [PMID: 19369200 PMCID: PMC2678454 DOI: 10.1073/pnas.0901617106] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2009] [Indexed: 11/18/2022] Open
Abstract
Metazoan embryogenesis is controlled by a limited number of signaling modules that are used repetitively at successive developmental stages. The development of social amoebas shows similar reiterated use of cAMP-mediated signaling. In the model Dictyostelium discoideum, secreted cAMP acting on 4 cAMP receptors (cARs1-4) coordinates cell movement during aggregation and fruiting body formation, and induces the expression of aggregation and sporulation genes at consecutive developmental stages. To identify hierarchy in the multiple roles of cAMP, we investigated cAR heterogeneity and function across the social amoeba phylogeny. The gene duplications that yielded cARs 2-4 occurred late in evolution. Many species have only a cAR1 ortholog that duplicated independently in the Polysphondylids and Acytostelids. Disruption of both cAR genes of Polysphondylium pallidum (Ppal) did not affect aggregation, but caused complete collapse of fruiting body morphogenesis. The stunted structures contained disorganized stalk cells, which supported a mass of cysts instead of spores; cAMP triggered spore gene expression in Ppal, but not in the cAR null mutant, explaining its sporulation defect. Encystation is the survival strategy of solitary amoebas, and lower taxa, like Ppal, can still encyst as single cells. Recent findings showed that intracellular cAMP accumulation suffices to trigger encystation, whereas it is a complementary requirement for sporulation. Combined, the data suggest that cAMP signaling in social amoebas evolved from cAMP-mediated encystation in solitary amoebas; cAMP secretion in aggregates prompted the starving cells to form spores and not cysts, and additionally organized fruiting body morphogenesis. cAMP-mediated aggregation was the most recent innovation.
Collapse
Affiliation(s)
- Yoshinori Kawabe
- College of Life Sciences, University of Dundee, Dundee, Angus, DD15EH, United Kingdom; and
| | - Takahiro Morio
- Graduate School of Life and Environmental Sciences, University of Tsukuba, Ibaraki, 305-8572, Japan
| | - John L. James
- College of Life Sciences, University of Dundee, Dundee, Angus, DD15EH, United Kingdom; and
| | - Alan R. Prescott
- Graduate School of Life and Environmental Sciences, University of Tsukuba, Ibaraki, 305-8572, Japan
| | - Yoshimasa Tanaka
- Graduate School of Life and Environmental Sciences, University of Tsukuba, Ibaraki, 305-8572, Japan
| | - Pauline Schaap
- College of Life Sciences, University of Dundee, Dundee, Angus, DD15EH, United Kingdom; and
| |
Collapse
|
3
|
Abstract
A fundamental goal of biology is to understand how novel phenotypes evolved through changes in existing genes. The Dictyostelia or social amoebas represent a simple form of multicellularity, where starving cells aggregate to build fruiting structures. This review summarizes efforts to provide a framework for investigating the genetic changes that generated novel morphologies in the Dictyostelia. The foundation is a recently constructed molecular phylogeny of the Dictyostelia, which was used to examine trends in the evolution of novel forms and in the divergence of genes that shape these forms. There is a major trend towards the formation of large unbranched fruiting bodies, which is correlated with the use of cyclic AMP (cAMP) as a secreted signal to coordinate cell aggregation. The role of cAMP in aggregation arose through co‐option of a pathway that originally acted to coordinate fruiting body formation. The genotypic changes that caused this innovation and the role of dynamic cAMP signaling in defining fruiting body size and pattern throughout social amoeba evolution are discussed. BioEssays 29:635–644, 2007. © 2007 Wiley Periodicals, Inc.
Collapse
Affiliation(s)
- Pauline Schaap
- College of Life Sciences, University of Dundee, MSI/WTB/JBC complex, Dow Street, Dundee DD1 5EH, UK.
| |
Collapse
|
4
|
van Es S, Kooistra RA, Schaap P. Two ras genes in Dictyostelium minutum show high sequence homology, but different developmental regulation from Dictyostelium discoideum rasD and rasG genes. Gene 1997; 187:93-7. [PMID: 9073071 DOI: 10.1016/s0378-1119(96)00729-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The social amoeba Dictyostelium discoideum expresses five ras genes at different stages of development. One of them, DdrasD is expressed during postaggregative development and transcription is induced by extracellular cAMP. A homologue of DdrasD, the DdrasG gene, is expressed exclusively during vegetative growth. We cloned two ras homologues Dmras1 and Dmras2 from the primitive species D. minutum, which show high homology to DdrasD and DdrasG and less homology to the other Ddras genes. In contrast to the DdrasD and DdrasG genes, both the Dmras1 and Dmras2 genes are expressed during the entire course of development. The expression levels are low during growth, increase at the onset of starvation and do not decrease until fruiting bodies have formed. Expression of neither Dmras1 or Dmras2 is regulated by cAMP. So even though the high degree of homology between the ras genes of different species suggests conservation of function, this function is apparently not associated with a specific developmental stage.
Collapse
Affiliation(s)
- S van Es
- Institute for Molecular Plant Sciences, University of Leiden, Wassenaarseweg, The Netherlands
| | | | | |
Collapse
|
5
|
Fontana DR, Price PL, Phillips JC. Cell-cell contact mediates cAMP secretion in Dictyostelium discoideum. DEVELOPMENTAL GENETICS 1991; 12:54-62. [PMID: 1646695 DOI: 10.1002/dvg.1020120111] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Cyclic adenosine 3':5' monophosphate (cAMP) and cell-cell contact regulate developmental gene expression in Dictyostelium discoideum. Developing D. discoideum amoebae synthesize and secrete cAMP following the binding of cAMP to their surface cAMP receptor, a response called cAMP signaling. We have demonstrated two responses of developing D. discoideum amoebae to cell-cell contact. Cell-cell contact elicits cAMP secretion and alters the amount of cAMP secreted in a subsequent cAMP signaling response. Depending upon experimental conditions, bacterial-amoebal contact and amoebal-amoebal contact can enhance or diminish the amount of cAMP secreted during a subsequent cAMP signaling response. We have hypothesized that cell-cell contact regulates D. discoideum development by altering cellular and extracellular levels of cAMP. To begin testing this hypothesis, these responses were further characterized. The two responses to cell-cell contact are independent, i.e., they can each occur in the absence of the other. The responses to cell-cell contact also have unique temperature dependences when compared to each other, cAMP signaling, and phagocytosis. This suggests that these four responses have unique steps in their transduction mechanisms. The secretion of cAMP in response to cell-cell contact appears to be a non-specific response; contact between D. discoideum amoebae and Enterobacter aerogenes, latex beads, or other amoebae elicits cAMP secretion. Despite the apparent similarities of the effects of bacterial-amoebal and amoebal-amoebal contact on the cAMP signaling response, this contact-induced response appears to be specific. Latex beads addition does not alter the magnitude of a subsequent cAMP signaling response.(ABSTRACT TRUNCATED AT 250 WORDS)
Collapse
Affiliation(s)
- D R Fontana
- Department of Microbiology, University of Minnesota, Minneapolis 55455
| | | | | |
Collapse
|
6
|
Fontana DR, Price PL. Cell-cell contact elicits cAMP secretion and alters cAMP signaling in Dictyostelium discoideum. Differentiation 1989. [DOI: 10.1111/j.1432-0436.1989.tb00746.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
7
|
|
8
|
|
9
|
|
10
|
Otte AP, Plomp MJ, Arents JC, Janssens PM, van Driel R. Production and turnover of cAMP signals by prestalk and prespore cells in Dictyostelium discoideum cell aggregates. Differentiation 1986; 32:185-91. [PMID: 3025046 DOI: 10.1111/j.1432-0436.1986.tb00572.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Dictyostelium discoideum prestalk cells and prespore cells from migrating slugs and culminating cell aggregates were isolated by Percoll density centrifugation. Several activities relevant to the generation, detection, and turnover of extracellular cyclic AMP (cAMP) signals were determined. It was found that: the two cell types have the same basal adenylate cyclase activity; prespore cells and prestalk cells are able to relay the extracellular cAMP signal equally well; intact prestalk cells show a threefold higher cAMP phosphodiesterase activity on the cell surface than prespore cells, whereas their cytosolic activity is the same; intact prestalk cells bind three to four times more cAMP than prespore cells; no large differences in cAMP metabolism and detection were observed between cells derived from migrating slugs and culminating aggregates. The results are discussed in relation to the possible morphogenetic role of extracellular cAMP in Dictyostelium cell aggregates. On the basis of the properties of the isolated cells we assume that a gradient of extracellular cAMP exists in Dictyostelium aggregates. This gradient appears to be involved in the formation and stabilization of the prestalk-prespore cell pattern.
Collapse
|
11
|
Schaap P, Wang M. Interactions between adenosine and oscillatory cAMP signaling regulate size and pattern in Dictyostelium. Cell 1986; 45:137-44. [PMID: 3006924 DOI: 10.1016/0092-8674(86)90545-3] [Citation(s) in RCA: 96] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
We present evidence for the hypothesis that in multicellular structures of Dictyostelium, production of adenosine by hydrolysis of cAMP near the tip region prevents both generation of competing tips and differentiation of prespore cells near the tip, and thus establishes a "prestalk" region. We demonstrate that adenosine affects the immunological prespore specific staining pattern in slugs in a manner opposite to cAMP:cAMP induces an increase of prespore antigen; adenosine induces a decrease. When endogenous adenosine is removed from slugs, prespore vacuoles are synthesized throughout the prestalk region. Adenosine was found to inhibit the induction of prespore differentiation by cAMP in an apparently competitive manner. It was also found that adenosine specifically increased the amount of tissue controlled by one tip, probably by inhibiting generation of competing oscillators. Removing endogenous adenosine from slugs resulted in a decrease of tip dominance.
Collapse
|
12
|
Kesbeke F, Haastert PJ, Schaap P. Cyclic AMP relay and cyclic AMP-induced cyclic GMP accumulation during development ofDictyostelium discoideum. FEMS Microbiol Lett 1986. [DOI: 10.1111/j.1574-6968.1986.tb01354.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
|
13
|
Wang M, Schaap P. Correlations between tip dominance, prestalk/prespore pattern, and CAMP-relay efficiency in slugs of Dictyostelium discoideum. Differentiation 1985. [DOI: 10.1111/j.1432-0436.1985.tb00506.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
|
14
|
|
15
|
Schaap P, van Driel RV. Induction of post-aggregative differentiation in Dictyostelium discoideum by cAMP. Evidence of involvement of the cell surface cAMP receptor. Exp Cell Res 1985; 159:388-98. [PMID: 2993006 DOI: 10.1016/s0014-4827(85)80012-4] [Citation(s) in RCA: 160] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Exogenous cAMP is known to induce post-aggregative differentiation in Dictyostelium discoideum under conditions that normal development is blocked. We have analysed the cyclic nucleotide specificity, the effect of modulation of the cAMP signal and the dose-response relationship of the induction of two independent markers of post-aggregative differentiation, i.e., a prespore cell-specific antigen detected by a monoclonal antibody, and the activity of glycogen phosphorylase. Our results confirm that high concentrations of cAMP (10(-6)-10(-3)M) are required for the induction of these markers. The cells are shown not to adapt to the cAMP signal. The cyclic nucleotide specificity of induction agrees with the specificity of the cell surface cAMP receptor, but is very dissimilar to the specificity of the intracellular cAMP-dependent protein kinase. It is thus unlikely that cAMP leaks into the cell and activates the cAMP-dependent protein kinase directly. Instead, the induction of post-aggregative differentiation by cAMP seems to be mediated by cell surface cAMP receptors.
Collapse
|