Analytical validation of innovative magneto-inertial outcomes: a controlled environment study.

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Study of the interaction between EFHC1, a protein mutated in juvenile myoclonic epilepsy, and the TTLL6 glutamylase. Analysis of its functional consequences

Etude de l'interaction entre EFHC1 et TTLL6, Ainsi que de leur implication fonctionnell

EFHC1/ Myoclinone 1 module les modifications post-traductionnelles des microtubules

Rationale: Juvenile myoclonic epilepsies (JME) are one of the most common forms of genetic generalized epilepsy. Genetic studies have shown that heterozygous mutations in EFHC1/Myoclonin1 are responsible for 3-22% of JME cases worldwide. The Myoclonin1 protein contains three DM10 domains of unknown function and an EF-hand domain. We have previously demonstrated that Myoclonin1 is a microtubule-associated protein involved in cell division and radial migration during neocortex development. In cells, this protein co-localized with specific structures rich in microtubules (MTs) such as the centrosome, the poles of the mitotic spindle or the motile cilia but not with cytoplasmic MTs. This suggests post-translational modifications (PTM) of MTs may be important for the interaction between Myoclonin1 and MTs Methods: We co-expressed the different enzymes catalyzing PTM of MTs with Myoclonin1 in U2OS cell line, and then performed immunocytochemistry and western blot analysis. We next performed pulldown and luciferase complementation assays to test protein interaction Results: With one of these enzymes, we observed a strong increase in PTM in the presence of Myoclonin- 1.Interestingly, the effect is observed even when a DM10 domain alone is co-expressed with the enzyme, suggesting for the first time a role for this domain. This suggests that Myoclonin1 may interact with and modulate the activity of this enzyme. By using luciferase complementation assay and pull down experiments, we could demonstrate that both proteins interact. Conclusions: Our data suggest Myoclonin-1 modulates specific PTM of MTs. This is of prime importance for microtubule dynamic and notably for neuroblast precursor migration during neocortex development. This could be the mechanism that explains why pathological forms of myoclonin-1 may affect brain development.Study of the interaction between EFHC1and TTLL6, and its functional implication

Myoclonin 1 modulates the post-translational modification of microtubules

Juvenile myoclonic epilepsy is one of the most common forms of generalized genetic epilepsy. Genetic studies have shown that heterozygous mutations in Myoclonin1 are responsible for 3-9% of clinical cases worldwide. This protein contains three DM10 domains of unknown function and an EF-hand domain. We have previously demonstrated that Myoclonin1 is a microtubule-associated protein involved in cell division and radial migration during neocortex development. In cells, this protein co-localized with specific structures rich in microtubules (MTs) such as the centrosome, the poles of the mitotic spindle or the motile cilia but not with cytoplasmic MTs. This suggests post-translational modifications (PTM) of MTs may be important for the interaction between Myoclonin1 and MTs. We have co-express the different enzymes catalyzing PTM of MTs with Myoclonin1 in U2OS cell line. With one of these enzymes, we observed a strong increase in PTM in the presence of Myoclonin-1. This suggests that Myoclonin1 may interact with and modulate the activity of this enzyme. By using luciferase complementation assay and pull down experiments, we could demonstrate that it is indeed the case. Interestingly, the effect is observed even when a DM10 domain alone is co-expressed with the enzyme, suggesting for the first time a role for this domain. In conclusion our data suggest myoclonin-1 modulates specific PTM of MTs. This is of prime importance for microtubule dynamic and notably for neuroblast precursor migration during neocortex development. This could be the mechanism that explains why pathological forms of myoclonin-1 affect brain development.Study of the interaction between EFHC1 and TTLL6, and its functional implication

Myoclonine 1 module les modifications post-traductionnel de la tubuline

Juvenile myoclonic epilepsy is one of the most common forms of generalized genetic epilepsy. Genetic studies have shown that heterozygous mutations in Myoclonin1 are responsible for 3-9% of clinical cases worldwide. This protein contains three DM10 domains of unknown function and an EF-hand domain. We have previously demonstrated that Myoclonin1 is a microtubule-associated protein involved in cell division and radial migration during neocortex development. In cells, this protein co-localized with specific structures rich in microtubules (MTs) such as the centrosome, the poles of the mitotic spindle or the motile cilia but not with cytoplasmic MTs. This suggests post-translational modifications (PTM) of MTs may be important for the interaction between Myoclonin1 and MTs. We have co-express the different enzymes catalyzing PTM of MTs with Myoclonin1 in U2OS cell line. With one of these enzymes, we observed a strong increase in PTM in the presence of Myoclonin-1. This suggests that Myoclonin1 may interact with and modulate the activity of this enzyme. By using luciferase complementation assay and pull down experiments, we could demonstrate that it is indeed the case. Interestingly, the effect is observed even when a DM10 domain alone is co-expressed with the enzyme, suggesting for the first time a role for this domain. In conclusion our data suggest myoclonin-1 modulates specific PTM of MTs. This is of prime importance for microtubule dynamic and notably for neuroblast precursor migration during neocortex development. This could be the mechanism that explains why pathological forms of myoclonin-1 affect brain development.Study of the interaction between EFHC1 and TTLL6, and its functional implication

EFHC1, a protein mutated in Juvenile Myoclonic Epilepsy, interacts with TTLL6 and modulates the level of tubulin polyglutamylation

EFHC1 is the most frequently mutated gene in Juvenile Myoclonic Epilepsy (JME) and encodes for a Microtubule Associated Protein (MAP) of unknown function. Interestingly, in ependymal cells of EFHC1 null-mutant (EFHC1-KO) mouse, a specific decrease of cilia beating is observed. Polyglutamylation is a crucial post-translational modification of tubulin (PMT) which plays a role in centriole stability, mitosis but also axoneme/cilia motility. In ependymal cells, beating behavior is due to the activity of the Tubulin Tyrosin Ligase like 6 (TTLL6). Taken together, these results suggest an interaction between EFHC1 and TLL6