کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
2039414 | 1073055 | 2016 | 13 صفحه PDF | دانلود رایگان |
• We describe an autoinhibitory regulation of UNC-104/KIF1A
• ARL-8 activates UNC-104 by releasing autoinhibition
• The autoinhibition of UNC-104 determines synaptic size and density
• The nucleotide state of ARL-8 determines synaptic size and density
SummaryKinesin motor proteins transport intracellular cargoes throughout cells by hydrolyzing ATP and moving along microtubule tracks. Intramolecular autoinhibitory interactions have been shown for several kinesins in vitro; however, the physiological significance of autoinhibition remains poorly understood. Here, we identified four mutations in the stalk region and motor domain of the synaptic vesicle (SV) kinesin UNC-104/KIF1A that specifically disrupt autoinhibition. These mutations augment both microtubule and cargo vesicle binding in vitro. In vivo, these mutations cause excessive activation of UNC-104, leading to decreased synaptic density, smaller synapses, and ectopic localization of SVs in the dendrite. We also show that the SV-bound small GTPase ARL-8 activates UNC-104 by unlocking the autoinhibition. These results demonstrate that the autoinhibitory mechanism is used to regulate the distribution of transport cargoes and is important for synaptogenesis in vivo.
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Journal: - Volume 16, Issue 8, 23 August 2016, Pages 2129–2141