71
views
0
recommends
+1 Recommend
0 collections
    0
    shares
      • Record: found
      • Abstract: found
      • Article: not found

      Tubulin tyrosination is a major factor affecting the recruitment of CAP-Gly proteins at microtubule plus ends

      research-article

      Read this article at

      ScienceOpenPublisherPMC
      Bookmark
          There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.

          Abstract

          Tubulin-tyrosine ligase (TTL), the enzyme that catalyzes the addition of a C-terminal tyrosine residue to α-tubulin in the tubulin tyrosination cycle, is involved in tumor progression and has a vital role in neuronal organization. We show that in mammalian fibroblasts, cytoplasmic linker protein (CLIP) 170 and other microtubule plus-end tracking proteins comprising a cytoskeleton-associated protein glycine-rich (CAP-Gly) microtubule binding domain such as CLIP-115 and p150 Glued, localize to the ends of tyrosinated microtubules but not to the ends of detyrosinated microtubules. In vitro, the head domains of CLIP-170 and of p150 Glued bind more efficiently to tyrosinated microtubules than to detyrosinated polymers. In TTL-null fibroblasts, tubulin detyrosination and CAP-Gly protein mislocalization correlate with defects in both spindle positioning during mitosis and cell morphology during interphase. These results indicate that tubulin tyrosination regulates microtubule interactions with CAP-Gly microtubule plus-end tracking proteins and provide explanations for the involvement of TTL in tumor progression and in neuronal organization.

          Related collections

          Most cited references44

          • Record: found
          • Abstract: found
          • Article: not found

          Cellular motility driven by assembly and disassembly of actin filaments.

          Motile cells extend a leading edge by assembling a branched network of actin filaments that produces physical force as the polymers grow beneath the plasma membrane. A core set of proteins including actin, Arp2/3 complex, profilin, capping protein, and ADF/cofilin can reconstitute the process in vitro, and mathematical models of the constituent reactions predict the rate of motion. Signaling pathways converging on WASp/Scar proteins regulate the activity of Arp2/3 complex, which mediates the initiation of new filaments as branches on preexisting filaments. After a brief spurt of growth, capping protein terminates the elongation of the filaments. After filaments have aged by hydrolysis of their bound ATP and dissociation of the gamma phosphate, ADF/cofilin proteins promote debranching and depolymerization. Profilin catalyzes the exchange of ADP for ATP, refilling the pool of ATP-actin monomers bound to profilin, ready for elongation.
            Bookmark
            • Record: found
            • Abstract: found
            • Article: not found

            The extracellular matrix guides the orientation of the cell division axis.

            The cell division axis determines the future positions of daughter cells and is therefore critical for cell fate. The positioning of the division axis has been mostly studied in systems such as embryos or yeasts, in which cell shape is well defined. In these cases, cell shape anisotropy and cell polarity affect spindle orientation. It remains unclear whether cell geometry or cortical cues are determinants for spindle orientation in mammalian cultured cells. The cell environment is composed of an extracellular matrix (ECM), which is connected to the intracellular actin cytoskeleton via transmembrane proteins. We used micro-contact printing to control the spatial distribution of the ECM on the substrate and demonstrated that it has a role in determining the orientation of the division axis of HeLa cells. On the basis of our analysis of the average distributions of actin-binding proteins in interphase and mitosis, we propose that the ECM controls the location of actin dynamics at the membrane, and thus the segregation of cortical components in interphase. This segregation is further maintained on the cortex of mitotic cells and used for spindle orientation.
              Bookmark
              • Record: found
              • Abstract: found
              • Article: not found

              Visualization of microtubule growth in cultured neurons via the use of EB3-GFP (end-binding protein 3-green fluorescent protein).

              Several microtubule binding proteins, including CLIP-170 (cytoplasmic linker protein-170), CLIP-115, and EB1 (end-binding protein 1), have been shown to associate specifically with the ends of growing microtubules in non-neuronal cells, thereby regulating microtubule dynamics and the binding of microtubules to protein complexes, organelles, and membranes. When fused to GFP (green fluorescent protein), these proteins, which collectively are called +TIPs (plus end tracking proteins), also serve as powerful markers for visualizing microtubule growth events. Here we demonstrate that endogenous +TIPs are present at distal ends of microtubules in fixed neurons. Using EB3-GFP as a marker of microtubule growth in live cells, we subsequently analyze microtubule dynamics in neurons. Our results indicate that microtubules grow slower in neurons than in glia and COS-1 cells. The average speed and length of EB3-GFP movements are comparable in cell bodies, dendrites, axons, and growth cones. In the proximal region of differentiated dendrites approximately 65% of EB3-GFP movements are directed toward the distal end, whereas 35% are directed toward the cell body. In more distal dendritic regions and in axons most EB3-GFP dots move toward the growth cone. This difference in directionality of EB3-GFP movements in dendrites and axons reflects the highly specific microtubule organization in neurons. Together, these results suggest that local microtubule polymerization contributes to the formation of the microtubule network in all neuronal compartments. We propose that similar mechanisms underlie the specific association of CLIPs and EB1-related proteins with the ends of growing microtubules in non-neuronal and neuronal cells.
                Bookmark

                Author and article information

                Journal
                J Cell Biol
                JCB
                The Journal of Cell Biology
                The Rockefeller University Press
                0021-9525
                1540-8140
                11 September 2006
                : 174
                : 6
                : 839-849
                Affiliations
                [1 ]Laboratoire du Cytosquelette, Institut National de la Santé et de la Recherche Médicale U366, Département Réponse et Dynamique Cellulaire, Commisariat à l'Energie Atomique Grenoble, 38054 Grenoble, France
                [2 ]Biologie du Cycle Cellulaire et de la Motilité, UMR144, Centre National de la Recherche Scientifique, Institut Curie, 75248 Paris, Cedex 05, France
                [3 ]Medical Research Council Centre for Developmental Neurobiology, King's College London, London SE1 1UL, England, UK
                [4 ]Department of Cell Biology and Genetics, Erasmus Medical Center, 3000 DR Rotterdam, Netherlands
                [5 ]Department of Physiology and Biophysics, University of Washington, Seattle, WA 98195
                [6 ]Department of Cell Biology, German Research Center for Biotechnology, D-38124 Braunschweig, Germany
                Author notes

                Correspondence to Didier Job: didier.job@ 123456cea.fr

                Article
                200512058
                10.1083/jcb.200512058
                2064338
                16954346
                4ee6edd2-ab43-4397-bed8-8c4498e758a8
                Copyright © 2006, The Rockefeller University Press
                History
                : 9 December 2005
                : 17 July 2006
                Categories
                Research Articles
                Article

                Cell biology
                Cell biology

                Comments

                Comment on this article