Olivier Urwyler

University of Zurich | UZH · Institut für Molekulare Biologie

Neuronal morphogenesis, integration into circuits, and remodeling of synaptic connections occur in temporally and spatially defined steps. Accordingly, the expression of proteins and specific protein isoforms that contribute to these processes must be controlled quantitatively in time and space. A wide variety of post-transcriptional regulatory mec...

Synaptic targeting with subcellular specificity is essential for neural circuit assembly. Developing neurons use mechanisms to curb promiscuous synaptic connections and to direct synapse formation to defined subcellular compartments. How this selectivity is achieved molecularly remains enigmatic. Here, we discover a link between mRNA poly(A)-tailin...

Compartmentalization of axons Neurons can spread branches far and wide across the central nervous system. One neuron can simultaneously contact several other neurons, amplifying network complexity. Studying the Drosophila brain, Urwyler et al. found that not all axon branches are the same, even within one neuron (see the Perspective by Falkner and...

Axonal branching contributes substantially to neuronal circuit complexity. Studies in Drosophila have shown that loss of Dscam1 receptor diversity can fully block axon branching in mechanosensory neurons. Here we report that cell-autonomous loss of the receptor tyrosine phosphatase 69D (RPTP69D) and loss of midline-localized Slit inhibit formation...

Determining direct synaptic connections of specific neurons in the central nervous system (CNS) is a major technical challenge in neuroscience. As a corollary, molecular pathways controlling developmental synaptogenesis in vivo remain difficult to address. Here, we present genetic tools for efficient and versatile labeling of organelles, cytoskelet...

The isoform diversity of the Drosophila Dscam1 receptor is important for neuronal self-recognition and self-avoidance. A canonical model suggests that homophilic binding of identical Dscam1 receptor isoforms on sister dendrites ensures self-avoidance even when only a single isoform is expressed. We detected a cell-intrinsic function of Dscam1 that...

Morphogenesis in multicellular organisms requires the careful coordination of cytoskeletal elements, dynamic regulation of cell adhesion and extensive cell migration. sosie (sie) is a novel gene required in various morphogenesis processes in Drosophila oogenesis. Lack of sie interferes with normal egg chamber packaging, maintenance of epithelial in...

Lack of Xpd does not cause centrosome inactivation. Proper γ-tubulin localization to the centrosomes of a cycle 12 xpdeE embryo with delayed histone H3 de-phosphorylation in anaphase. Scale bar represents 10 µm. (1.85 MB PDF)

Spindle dynamics and lack of division coordination in an xpdeE embryo. Movie of G147::GFP expression in xpdeE embryos. (9.95 MB MPG)

(1) Only the genotype of the 2nd chromosome is indicated. “Df” stands for Df(2R)K11. The flies are the offspring of the cross w; xpdP/CyO females crossed with w P[w+ xpd+]/Y; Df(2R)K11/b Tft males. “w”: X chromosome carrying a recessive white eye color mutation. “Y”: Y chromosome. “CyO”: Balancer for the second chromosome preventing recombination a...

Spindle dynamics of wild-type embryos. Movie of G147::GFP expression in wild-type embryos. (10.18 MB MPG)

The trimeric CAK complex functions in cell cycle control by phosphorylating and activating Cdks while TFIIH-linked CAK functions in transcription. CAK also associates into a tetramer with Xpd, and our analysis of young Drosophila embryos that do not require transcription now suggests a cell cycle function for this interaction. xpd is essential for...

Effect of amino acid 103 on BicD localization (0.57 MB PDF)

Protein phosphorylation is involved in posttranslational control of essentially all biological processes. Using mass spectrometry, recent analyses of whole phosphoproteomes led to the identification of numerous new phosphorylation sites. However, the function of most of these sites remained unknown. We chose the Drosophila Bicaudal-D protein to est...

Drosophila arginine methyl-transferase 4 (DART4) belongs to the type I class of arginine methyltransferases. It catalyzes the methylation of arginine residues to monomethylarginines and asymmetrical dimethylarginines. The DART4 sequence is highly similar to mammalian PRMT4/CARM1, and DART4 substrate specificity has been conserved, too. Recently it...