Cyclic AMP induction of Dictyostelium prespore gene expression requires autophagy
| Autor: | Yamada, Yoko, Schaap, Pauline |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2019 |
| Předmět: |
Spores
cAMP receptors fungi Cell-type specialization Genes Protozoan Gene Expression Regulation Developmental Cell Differentiation Autophagy-Related Protein 7 Cyclic AMP-Dependent Protein Kinases Article Endocytosis atg9 Phenotype atg7 Sporulation Ammonia Mutagenesis atg5 Mutation Autophagy Cyclic AMP Dictyostelium Phosphorylation Biomarkers Transcription Factors |
| Zdroj: | Developmental Biology |
| ISSN: | 1095-564X 0012-1606 |
| Popis: | Dictyostelium discoideum amoebas display colonial multicellularity where starving amoebas aggregate to form migrating slugs and fruiting bodies consisting of spores and three supporting cell types. To resolve the cell signalling mechanism that control sporulation, we use insertional mutagenesis of amoebas transformed with fusion constructs of spore genes and red fluorescent protein. We identified the defective gene in a mutant lacking spore gene expression as the autophagy gene Atg7. Directed knock-out of atg7 and of autophagy genes like atg5 and atg9 yielded a similar phenotype, with lack of viable spores and excessive differentiation of stalk cells. The atg7-, atg5- and atg9- cells were specifically defective in cAMP induction of prespore genes, but showed enhanced cAMP stimulation of prestalk genes at the same developmental stage. The lack of prespore gene induction in the autophagy mutants was not due to deleterious effects of loss of autophagy on known components of the cAMP pathway, such as cAMP receptors and their cAMP-induced phosphorylation and internalization, PKA and the transcription factors SpaA and GbfA, or to lack of NH3 production by proteolysis, which was previously suggested to stimulate the spore pathway. Our continued mutagenesis approach is the most likely to yield the intriguing link between autophagy and prespore gene induction. Highlights • A screen for Dictyostelium sporulation mutants identified autophagy gene atg7. • Atg7-, atg5-and atg9-cells cannot form viable spores, but show normal stalk formation. • Atg7-, atg5-and atg9-are specifically defective in cAMP induction of prespore genes. • Atg7-, atg5-and atg9-show normal to enhanced cAMP induction of prestalk genes. • PKA overexpression does not restore sporulation in autophagy mutants. |
| Databáze: | OpenAIRE |
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