TY - JOUR T1 - Katanin p60-like1 Promotes Microtubule Growth and Terminal Dendrite Stability in the Larval Class IV Sensory Neurons of <em>Drosophila</em> JF - The Journal of Neuroscience JO - J. Neurosci. SP - 11631 LP - 11642 DO - 10.1523/JNEUROSCI.0729-12.2012 VL - 32 IS - 34 AU - Andrea Stewart AU - Asako Tsubouchi AU - Melissa M. Rolls AU - W. Daniel Tracey AU - Nina Tang Sherwood Y1 - 2012/08/22 UR - http://www.jneurosci.org/content/32/34/11631.abstract N2 - Dendrite shape is considered a defining component of neuronal function. Yet, the mechanisms specifying diverse dendritic morphologies, and the extent to which their function depends on these morphologies, remain unclear. Here, we demonstrate a requirement for the microtubule-severing protein katanin p60-like 1 (Kat-60L1) in regulating the elaborate dendrite morphology and nocifensive functions of Drosophila larval class IV dendritic arborization neurons. Kat-60L1 mutants exhibit diminished responsiveness to noxious mechanical and thermal stimuli. Class IV dendrite branch number and length are also reduced, supporting a correspondence between neuronal function and the full extent of the dendritic arbor. These arborization defects occur particularly in late larval development, and live imaging reveals that Kat-60L1 is required for dynamic, filopodia-like nascent branches to stabilize during this stage. Mutant dendrites exhibit fewer EB1-GFP-labeled microtubules, suggesting that Kat-60L1 increases polymerizing microtubules to establish terminal branch stability and full arbor complexity. Although loss of the related microtubule-severing protein Spastin also reduces the class IV dendrite arbor, microtubule polymerization within dendrites is unaffected. Conversely, Spastin overexpression destroys stable microtubules within these neurons, while Kat-60L1 has no effect. Kat-60L1 thus sculpts the class IV dendritic arbor through microtubule regulatory mechanisms distinct from Spastin. Our data support differential roles of microtubule-severing proteins in regulating neuronal morphology and function, and provide evidence that dendritic arbor development is the product of multiple pathways functioning at distinct developmental stages. ER -