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[P67]: Cell fate specification and axonogenesis in neurons fate mapped from the embryonic rhombic lip
Author(s) -
Machold R.,
Klein C.,
Fishell G.
Publication year - 2006
Publication title -
international journal of developmental neuroscience
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.761
H-Index - 88
eISSN - 1873-474X
pISSN - 0736-5748
DOI - 10.1016/j.ijdevneu.2006.09.129
Subject(s) - center (category theory) , citation , embryonic stem cell , library science , cell fate determination , computer science , biology , genetics , chemistry , gene , transcription factor , crystallography
The neuronal synapse is an asymmetric structure consisting of pre and post-synaptic terminals in direct apposition. Synapse formation is a highly regulated process requiring the interaction of many genetic pathways. To identifying genes that are required for the proper formation of synapses we are using the GABAergic nervous system of C. elegans as our model system. C. elegans is an excellent model system due to its strong genetics and characterized and invariant nervous system. Fluorescently tagged synaptic proteins allow for the visualization of synapses in live animals and thus the identification of synapse mutants through genetic screens. We have identified a protein complex that controls synapse morphology. This SCF ubiquitin ligase complex consists of the F-box protein FSN-1, the RING finger protein RPM-1, Skp1, and Cullin. This complex is required pre-synaptically and is localized to the peri-active zone. We hypothesize that this protein complex controls synapse formation by down regulating synapse-promoting factors through an ubiquitin mediated process. We have identified a possible target or downstream effector of synapse formation in the receptor protein tyrosine kinase scd2 (suppressor of constitutive dauer). We have observed that protein levels of an SCD-2::GFP fusion protein increase in the absence of fsn-1 in vivo. SCD2 ubiquitination is currently being tested. We have shown that loss of scd-2 will partially rescue the synapse defects of fsn1 and rpm-1, and suppression of fsn-1 defects is specific for alleles of scd-2 that are defective in the C-terminal kinase. The incomplete suppression of fsn-1 by scd-2 suggests the existence of other pathways regulated by fsn-1. We are in the process of identifying other components of signaling pathways through which fsn-1 regulates synapse morphology.