Kim, Joanne SMLilley, Brendan NeilZhang, ChaoShokat, Kevan MSanes, JoshuaZhen, Mei2010-10-012008Kim, Joanne SM, Brendan N. Lilley, Chao Zhang, Kevan M. Shokat, Joshua R. Sanes, and Mei Zhen. 2008. A chemical-genetic strategy reveals distinct temporal requirements for SAD-1 kinase in neuronal polarization and synapse formation. Neural Development 3:23.1749-8104http://nrs.harvard.edu/urn-3:HUL.InstRepos:4455249Background: Neurons assemble into a functional network through a sequence of developmental processes including neuronal polarization and synapse formation. In Caenorhabditis elegans, the serine/threonine SAD-1 kinase is essential for proper neuronal polarity and synaptic organization. To determine if SAD-1 activity regulates the establishment or maintenance of these neuronal structures, we examined its temporal requirements using a chemical-genetic method that allows for selective and reversible inactivation of its kinase activity in vivo. Results: We generated a PP1 analog-sensitive variant of SAD-1. Through temporal inhibition of SAD-1 kinase activity we show that its activity is required for the establishment of both neuronal polarity and synaptic organization. However, while SAD-1 activity is needed strictly when neurons are polarizing, the temporal requirement for SAD-1 is less stringent in synaptic organization, which can also be re-established during maintenance. Conclusion: This study reports the first temporal analysis of a neural kinase activity using the chemical-genetic system. It reveals that neuronal polarity and synaptic organization have distinct temporal requirements for SAD-1.en-USJournal Article2010-10-0110.1186/1749-8104-3-23