scholarly journals ATAT1-enriched vesicles promote microtubule acetylation via axonal transport

2019 ◽  
Author(s):  
Aviel Even ◽  
Giovanni Morelli ◽  
Chiara Scaramuzzino ◽  
Ivan Gladwyn-Ng ◽  
Romain Le Bail ◽  
...  
Keyword(s):  
Axonal Transport ◽  
Vesicular Transport ◽  
Microtubule Dynamics ◽  
Tubulin Acetylation ◽  
Cytosolic Side ◽  
Neuronal Vesicles ◽  
Β Tubulin

Microtubules are polymerized dimers of α- and β-tubulin that underlie a broad range of cellular activities. Acetylation of α-tubulin by the acetyl-transferase ATAT1 modulates microtubule dynamics and functions in neurons. However, it remains unclear how and why this enzyme acetylates microtubules over long distances in axons. Here, we show that loss of ATAT1 impairs axonal transport in neurons and cell free motility assays confirm a requirement of tubulin acetylation for proper bidirectional vesicular transport. Moreover, we demonstrate that the main cellular pool of ATAT1 is transported at the cytosolic side of neuronal vesicles that are moving along axons. Altogether, our data suggest that axonal transport of ATAT1-enriched vesicles is the predominant driver of α-tubulin acetylation in axons.

scholarly journals ATAT1-enriched vesicles promote microtubule acetylation via axonal transport

2019 ◽  
Vol 5 (12) ◽  
pp. eaax2705 ◽  
Author(s):  
Aviel Even ◽  
Giovanni Morelli ◽  
Loïc Broix ◽  
Chiara Scaramuzzino ◽  
Silvia Turchetto ◽  
...  
Keyword(s):  
Axonal Transport ◽  
Vesicular Transport ◽  
Microtubule Dynamics ◽  
Tubulin Acetylation ◽  
Cytosolic Side ◽  
Neuronal Vesicles ◽  
Β Tubulin

Microtubules are polymerized dimers of α- and β-tubulin that underlie a broad range of cellular activities. Acetylation of α-tubulin by the acetyltransferase ATAT1 modulates microtubule dynamics and functions in neurons. However, it remains unclear how this enzyme acetylates microtubules over long distances in axons. Here, we show that loss of ATAT1 impairs axonal transport in neurons in vivo, and cell-free motility assays confirm a requirement of α-tubulin acetylation for proper bidirectional vesicular transport. Moreover, we demonstrate that the main cellular pool of ATAT1 is transported at the cytosolic side of neuronal vesicles that are moving along axons. Together, our data suggest that axonal transport of ATAT1-enriched vesicles is the predominant driver of α-tubulin acetylation in axons.

scholarly journals β-Tubulin C354 Mutations that Severely Decrease Microtubule Dynamics Do Not Prevent Nuclear Migration in Yeast

2002 ◽  
Vol 13 (8) ◽  
pp. 2919-2932 ◽  
Author(s):  
Mohan L. Gupta ◽  
Claudia J. Bode ◽  
Douglas A. Thrower ◽  
Chad G. Pearson ◽  
Kathy A. Suprenant ◽  
...  
Keyword(s):  
Essential Gene ◽  
Dynamic Properties ◽  
Microtubule Dynamics ◽  
Cytoplasmic Microtubule ◽  
Bud Emergence ◽  
Spindle Elongation ◽  
Mutant Cells ◽  
Β Tubulin

Microtubule dynamics are influenced by interactions of microtubules with cellular factors and by changes in the primary sequence of the tubulin molecule. Mutations of yeast β-tubulin C354, which is located near the binding site of some antimitotic compounds, reduce microtubule dynamicity greater than 90% in vivo and in vitro. The resulting intrinsically stable microtubules allowed us to determine which, if any, cellular processes are dependent on dynamic microtubules. The average number of cytoplasmic microtubules decreased from 3 in wild-type to 1 in mutant cells. The single microtubule effectively located the bud site before bud emergence. Although spindles were positioned near the bud neck at the onset of anaphase, the mutant cells were deficient in preanaphase spindle alignment along the mother-bud axis. Spindle microtubule dynamics and spindle elongation rates were also severely depressed in the mutants. The pattern and extent of cytoplasmic microtubule dynamics modulation through the cell cycle may reveal the minimum dynamic properties required to support growth. The ability to alter intrinsic microtubule dynamics and determine the in vivo phenotype of cells expressing the mutant tubulin provides a critical advance in assessing the dynamic requirements of an essential gene function.

scholarly journals β-Tubulin mutations that cause severe neuropathies disrupt axonal transport

2013 ◽  
Vol 32 (10) ◽  
pp. 1352-1364 ◽  
Author(s):  
Shinsuke Niwa ◽  
Hironori Takahashi ◽  
Nobutaka Hirokawa
Keyword(s):  
Axonal Transport ◽  
Tubulin Mutations ◽  
Β Tubulin

scholarly journals Dynein efficiently navigates the dendritic cytoskeleton to drive the retrograde trafficking of BDNF/TrkB signaling endosomes

2017 ◽  
Vol 28 (19) ◽  
pp. 2543-2554 ◽  
Author(s):  
Swathi Ayloo ◽  
Pedro Guedes-Dias ◽  
Amy E. Ghiretti ◽  
Erika L. F. Holzbaur
Keyword(s):  
Real Time ◽  
Axonal Transport ◽  
Hippocampal Neurons ◽  
Cytoplasmic Dynein ◽  
Microtubule Dynamics ◽  
Neuronal Function ◽  
Retrograde Trafficking ◽  
Basic Understanding ◽  
Dependent Transport ◽  
Dynamic Microtubule

The efficient transport of cargoes within axons and dendrites is critical for neuronal function. Although we have a basic understanding of axonal transport, much less is known about transport in dendrites. We used an optogenetic approach to recruit motor proteins to cargo in real time within axons or dendrites in hippocampal neurons. Kinesin-1, a robust axonal motor, moves cargo less efficiently in dendrites. In contrast, cytoplasmic dynein efficiently navigates both axons and dendrites; in both compartments, dynamic microtubule plus ends enhance dynein-dependent transport. To test the predictions of the optogenetic assay, we examined the contribution of dynein to the motility of an endogenous dendritic cargo and found that dynein inhibition eliminates the retrograde bias of BDNF/TrkB trafficking. However, inhibition of microtubule dynamics has no effect on BDNF/TrkB motility, suggesting that dendritic kinesin motors may cooperate with dynein to drive the transport of signaling endosomes into the soma. Collectively our data highlight compartment-specific differences in kinesin activity that likely reflect specialized tuning for localized cytoskeletal determinants, whereas dynein activity is less compartment specific but is more responsive to changes in microtubule dynamics.

scholarly journals Disruption of The Psychiatric Risk Gene Ankyrin 3 Enhances Microtubule Dynamics Through GSK3/CRMP2 Signaling

2018 ◽  
Author(s):  
Jacob C Garza ◽  
Xiaoli Qi ◽  
Klaudio Gjeluci ◽  
Melanie P Leussis ◽  
Himanish Basu ◽  
...  
Keyword(s):  
Psychiatric Illness ◽  
Molecular Mechanisms ◽  
Glycogen Synthase ◽  
Binding Protein ◽  
Neuronal Model ◽  
Microtubule Dynamics ◽  
Model Systems ◽  
Altered Expression ◽  
Risk Gene ◽  
Tubulin Acetylation

AbstractThe ankyrin 3 gene (ANK3) is a well-established risk gene for psychiatric illness, but the mechanisms underlying its pathophysiology remain elusive. We examined the molecular effects of disrupting brain-specific Ank3 isoforms in mouse and neuronal model systems. RNA sequencing of hippocampus from Ank3+/- and Ank3+/+ mice identified altered expression of 282 genes that were enriched for microtubule-related functions. Results were supported by increased expression of microtubule end-binding protein 3 (EB3), an indicator of microtubule dynamics, in Ank3+/- mouse hippocampus. Live-cell imaging of EB3 movement in primary neurons from Ank3+/- mice revealed impaired elongation of microtubules. Using a CRISPR-dCas9-KRAB transcriptional repressor in mouse neuro-2a cells, we determined that repression of brain-specific Ank3 increased EB3 expression, decreased tubulin acetylation, and increased the soluble:polymerized tubulin ratio, indicating enhanced microtubule dynamics. These changes were rescued by inhibition of glycogen synthase kinase 3 (GSK3) with lithium or CHIR99021, a highly selective GSK3 inhibitor. Brain-specific Ank3 repression in neuro-2a cells increased GSK3 activity (reduced inhibitory phosphorylation) and elevated collapsin response mediator protein 2 (CRMP2) phosphorylation, a known GSK3 substrate and microtubule-binding protein. Pharmacological inhibition of CRMP2 activity attenuated the rescue of EB3 expression and tubulin polymerization in Ank3 repressed cells by lithium or CHIR99021, suggesting microtubule instability induced by Ank3 repression is dependent on CRMP2 activity. Taken together, our data indicate that aNK3 functions in neuronal microtubule dynamics through GSK3 and its downstream substrate CRMP2. These findings reveal cellular and molecular mechanisms underlying brain-specific ANK3 disruption that may be related to its role in psychiatric illness.

scholarly journals Mutation of Ser172 in Yeast β Tubulin Induces Defects in Microtubule Dynamics and Cell Division

PLoS ONE ◽  
2010 ◽  
Vol 5 (10) ◽  
pp. e13553 ◽  
Author(s):  
Fabrice Caudron ◽  
Eric Denarier ◽  
Jenny-Constanza Thibout-Quintana ◽  
Jacques Brocard ◽  
Annie Andrieux ◽  
...  
Keyword(s):  
Cell Division ◽  
Microtubule Dynamics ◽  
Β Tubulin

scholarly journals The dual role of fission yeast Tbc1/cofactor C orchestrates microtubule homeostasis in tubulin folding and acts as a GAP for GTPase Alp41/Arl2

2013 ◽  
Vol 24 (11) ◽  
pp. 1713-1724 ◽  
Author(s):  
Risa Mori ◽  
Takashi Toda
Keyword(s):  
Fission Yeast ◽  
Molecular Level ◽  
Dual Role ◽  
Small Gtpase ◽  
Microtubule Dynamics ◽  
Regulatory Proteins ◽  
Dependent Manner ◽  
Continuous Cycling ◽  
Β Tubulin

Supplying the appropriate amount of correctly folded α/β-tubulin heterodimers is critical for microtubule dynamics. Formation of assembly-competent heterodimers is remarkably elaborate at the molecular level, in which the α- and β-tubulins are separately processed in a chaperone-dependent manner. This sequential step is performed by the tubulin-folding cofactor pathway, comprising a specific set of regulatory proteins: cofactors A–E. We identified the fission yeast cofactor: the orthologue of cofactor C, Tbc1. In addition to its roles in tubulin folding, Tbc1 acts as a GAP in regulating Alp41/Arl2, a highly conserved small GTPase. Of interest, the expression of GDP- or GTP-bound Alp41 showed the identical microtubule loss phenotype, suggesting that continuous cycling between these forms is important for its functions. In addition, we found that Alp41 interacts with Alp1D, the orthologue of cofactor D, specifically when in the GDP-bound form. Intriguingly, Alp1D colocalizes with microtubules when in excess, eventually leading to depolymerization, which is sequestered by co-overproducing GDP-bound Alp41. We present a model of the final stages of the tubulin cofactor pathway that includes a dual role for both Tbc1 and Alp1D in opposing regulation of the microtubule.

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