Project description:In many eukaryotes, mRNAs containing specific AU-rich motifs are regulated by proteins of the tristetraprolin (TTP) family, which bind to these motifs through a tandem zinc finger (TZF) domain. This binding leads to promotion of subsequent deadenylation and decay, partly through a conserved carboxyl-terminal CNOT1 binding domain. We explored the physiological role of the single TTP family member (TtpA) expressed in Dictyostelium discoideum. This study shows the effect of a carboxyl-terminal truncation (ttpA-D450trx), which removed the predicted CNOT1 binding domain, evaluated in amebae in growth medium during surface culture. The cells exhibited external and gene expression phenotypes that were very similar to those of two distinct null mutants, raising the possibility that this domain is necessary for TtpA-promoted mRNA decay in this species.
Project description:In many eukaryotes, mRNAs containing specific AU-rich motifs are regulated by proteins of the tristetraprolin (TTP) family, which bind to these motifs through a tandem zinc finger (TZF) domain. This binding leads to promotion of subsequent deadenylation and decay, partly through a conserved carboxyl-terminal CNOT1 binding domain. We explored the physiological role of the single TTP family member (TtpA) expressed in Dictyostelium discoideum. This study shows the effect of an insertional mutation within the TZF domain (ttpA-C240ins), which creates a null genotype, evaluated in amebae in growth medium during surface culture and liquid culture under axenic conditions. The mutant cells exhibited severe growth defects and a multinucleate phenotype during liquid culture, but not in surface culture.
Project description:In many eukaryotes, mRNAs containing specific AU-rich motifs are regulated by proteins of the tristetraprolin (TTP) family, which bind to these motifs through a tandem zinc finger (TZF) domain. This binding leads to promotion of subsequent deadenylation and decay, partly through a conserved carboxyl-terminal CNOT1 binding domain. We explored the physiological role of the single TTP family member (TtpA) expressed in Dictyostelium discoideum. This study shows the effect of an insertional mutation in the TZF domain (ttpA-C240ins), which disrupted the TZF RNA binding domain, evaluated in amebae in axenic conditions in growth medium during surface culture, and during short term (2 and 6 hours) nutrient deprivation. RNA-Seq analysis was performed on WT and mutant cells in parallel during this short time course.
Project description:In many eukaryotes, mRNAs containing specific AU-rich motifs are regulated by proteins of the tristetraprolin (TTP) family, which bind to these motifs through a tandem zinc finger (TZF) domain. This binding leads to promotion of subsequent deadenylation and decay, partly through a conserved carboxyl-terminal CNOT1 binding domain. We explored the physiological role of the single TTP family member (TtpA) expressed in Dictyostelium discoideum. This study shows the effect of three distinct putative null mutations in the ttpA gene on transcript expression in amebae in growth medium during surface culture under axenic conditions. The cells exhibited similar external and gene expression phenotypes, suggesting that they are all null mutants, despite two different types of mutations (two frame shifts and one amino acid substitution).
Project description:Knockout mutants of polyketide synthase genes were generated (pks1, pks2, pks3, pks14, pks18, pks37) and compared to wild-type AX2 strain of Dictyostelium discoideum using Agilent custom microarrays. The Dictyostelium cells were harvested at eight developmental stages (Amoeboid, Intiation of starvation, loose aggregate, Streaming, Mound, Slug, early culminant, Fruiting body) and subjected to microarray based expression profiling.