Thu, 21 Aug 2008 15:28:02 BST CiteULike: lechristophe Puthenveedu http://www.citeulike.org/user/lechristophe/author/Puthenveedu CiteULike.org en-gb Copyright © 2004-2008 citeulike.org http://www.citeulike.org/user/lechristophe/article/1109613 <i>Cell, Vol. 128, No. 3. (9 February 2007), pp. 547-560.</i><br /><br />Summary Gap junctions are intercellular channels that connect the cytoplasms of adjacent cells. For gap junctions to properly control organ formation and electrical synchronization in the heart and the brain, connexin-based hemichannels must be correctly targeted to cell-cell borders. While it is generally accepted that gap junctions form via lateral diffusion of hemichannels following microtubule-mediated delivery to the plasma membrane, we provide evidence for direct targeting of hemichannels to cell-cell junctions through a pathway that is dependent on microtubules; through the adherens-junction proteins N-cadherin and [beta]-catenin; through the microtubule plus-end-tracking protein (+TIP) EB1; and through its interacting protein p150(Glued). Based on live cell microscopy that includes fluorescence recovery after photobleaching (FRAP), total internal reflection fluorescence (TIRF), deconvolution, and siRNA knockdown, we propose that preferential tethering of microtubule plus ends at the adherens junction promotes delivery of connexin hemichannels directly to the cell-cell border. These findings support an unanticipated mechanism for protein delivery to points of cell-cell contact. Microtubule Plus-End-Tracking Proteins Target Gap Junctions Directly from the Cell Interior to Adherens Junctions Robin Shaw Alex Fay Manojkumar Puthenveedu Mark von Zastrow Yuh-Nung Jan Lily Jan doi:10.1016/j.cell.2006.12.037 Cell, Vol. 128, No. 3. (9 February 2007), pp. 547-560. 2007-02-16T10:36:08-00:00 2007 Cell 128 3 547 560 adhesion cytosqueleton intracellular live_cell_imaging membrane_insertion microscopy targeting tirf trafficking http://www.citeulike.org/user/lechristophe/article/977948 <i>Neuron, Vol. 52, No. 5. (7 December 2006), pp. 803-816.</i><br /><br />SummaryAxonal Kv1 channels regulate action potential propagation--an evolutionarily conserved function important for the control of motor behavior as evidenced from the linkage of human Kv1 channel mutations to myokymia/episodic ataxia type 1 (EA1) and the Shaker mutant phenotype in Drosophila. To search for the machinery that mediates axonal targeting of Kv1 channels composed of both [alpha] and [beta] subunits, we first demonstrate that Kv[beta]2 is responsible for targeting Kv1 channels to the axon. Next, we show that Kv[beta]2 axonal targeting depends on its ability to associate with the microtubule (MT) plus-end tracking protein (+TIP) EB1. Not only do Kv[beta]2 and EB1 move in unison down the axon, Brefeldin A-sensitive Kv1-containing vesicles can also be found at microtubule ends near the cell membrane. In addition, we found that Kv[beta]2 associates with KIF3/kinesin II as well. Indeed, Kv1 channels rely on both KIF3/kinesin II and EB1 for their axonal targeting. The Microtubule Plus-End Tracking Protein EB1 Is Required for Kv1 Voltage-Gated K+ Channel Axonal Targeting Chen Gu Wei Zhou Manojkumar Puthenveedu Mingxuan Xu Yuh Jan Lily Jan doi:10.1016/j.neuron.2006.10.022 Neuron, Vol. 52, No. 5. (7 December 2006), pp. 803-816. 2006-12-07T14:13:14-00:00 2006 Neuron 52 5 803 816 axon cytosqueleton ion_channels kv targeting tirf http://www.citeulike.org/user/lechristophe/article/918605 <i>Cell, Vol. 127, No. 1. (6 October 2006), pp. 113-124.</i><br /><br />Clathrin-coated pits (CCPs) are generally considered a uniform population of endocytic machines containing mixed constitutive and regulated membrane cargo. Contrary to this view, we show that regulated endocytosis of G protein-coupled receptors (GPCRs) occurs preferentially through a subset of CCPs. Significantly, GPCR-containing CCPs are also functionally distinct, as their surface residence time is regulated locally by GPCR cargo via PDZ-dependent linkage to the actin cytoskeleton. Such cargo-regulated CCPs show delayed recruitment of dynamin and can undergo an abortive event in which clathrin coats separate from the plasma membrane without concomitant receptor endocytosis. Segregation of cargo into CCP subsets, combined with cargo-dependent control of CCP dynamics, suggests a simple kinetic mechanism to generate functional specialization early in the endocytic pathway and reduce competition between diverse endocytic cargo. Cargo regulates clathrin-coated pit dynamics. MA Puthenveedu M von Zastrow doi:10.1016/j.cell.2006.08.035 Cell, Vol. 127, No. 1. (6 October 2006), pp. 113-124. 2006-10-30T16:10:33-00:00 2006 Cell 0092-8674 127 1 113 124 clathrin endocytosis tirf http://www.citeulike.org/user/lechristophe/article/600483 <i>Nature Neuroscience, Vol. 9, No. 5. (09 April 2006), pp. 622-627.</i><br /><br />Many neural signaling receptors are regulated by endocytosis, but little is known about receptor insertion into the plasma membrane. Time-lapse imaging of the beta2 adrenergic receptor expressed in cultured rat hippocampal neurons, using pH-sensitive green fluorescent protein tagging and total internal reflection fluorescence microscopy, resolved distinct vesicular fusion events mediating receptor insertion into the somatodendritic plasma membrane. A 'transient' insertion mode resulted in rapid lateral dispersion of receptors immediately after insertion. A 'persistent' insertion mode resulted in the retention of inserted receptors in surface-accessible domains, which were relatively immobile for a prolonged 'wait' period before dispersing laterally. Distinct insertion modes were oppositely regulated by receptor activation and by mechanisms differing in their dependence on the signaling effector cyclic AMP-dependent protein kinase. These results reveal a new mechanism for homeostatic regulation of postsynaptic signaling and a 'kiss-and-wait' mode of regulated membrane protein insertion in neurons. Distinct modes of regulated receptor insertion to the somatodendritic plasma membrane Guillermo Yudowski Manojkumar Puthenveedu Mark von Zastrow doi:10.1038/nn1679 Nature Neuroscience, Vol. 9, No. 5. (09 April 2006), pp. 622-627. 2006-04-25T16:30:24-00:00 2006 Nature Neuroscience 1097-6256 9 5 622 627 Nature Publishing Group exocytosis gpcr live_cell_imaging membrane_insertion microscopy pharmacology somatodendritic tirf