Autoinhibition of TBCB regulates EB1-mediated microtubule dynamics

Carranza, Gerardo; Castaño, Raquel; Fanarraga, Mónica L.; Villegas, Juan; Gonçalves, João; Soares, Helena; Ávila, Jesús; Marenchino, Marco; Campos-Olivas, Ramón; Montoya, Guillermo; Zabala, Juan Carlos

doi:10.1007/s00018-012-1114-2

Cited by 21 publications

(47 citation statements)

References 42 publications

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“…Whereas TBCE interacts with and dissociates the tubulin dimer, a stable complex is formed between this cofactor and a-tubulin only when TBCB is present (Kortazar et al, 2007). Although previous studies have suggested that there is an association between TBCB and TBCE (Grynberg et al, 2003;Kortazar et al, 2007), the only direct physical interaction characterized to date is between TBCE and the acidic TBCB Cterminal tail (Carranza et al, 2013). Analysis of the molecular architecture of the aEB complex suggests that TBCB interacts with TBCE, whereas there appears to be no notable interaction between TBCB and a-tubulin in the ternary complex.…”

Section: Discussionmentioning

confidence: 98%

“…To better understand the turnover process, we cloned, overexpressed and purified human TBCB and TBCE (Kortazar et al, 2007;Carranza et al, 2013) and analyzed their ability to dissociate tubulin dimers ( Fig. 1; supplementary material Fig.…”

Section: Characterization Of A-tubulin-b-tubulin Dissociation By Tbcementioning

confidence: 99%

“…6B). Second, that TBCE and TBCB have recently been shown to form a transient complex before tubulin dimer dissociation -this interaction is mediated by the last three residues of the TBCB C-terminal domain (DEI), similar to the atubulin C-terminal EEY motif (Carranza et al, 2013), and the TBCB and TBCE CAP-Gly domains must therefore make contact. Finally, that the TBCBcg mutant assists tubulin dimer dissociation mediated by TBCE (Fig.…”

Section: Structure Of the Human Tbce Ubl Domainmentioning

confidence: 99%

“…These cofactors interact differentially with a-or b-tubulin in a pathway that converges to control tubulin dimer formation (Fontalba et al, 1993;Tian et al, 1999). TBCE and TBCB are specific cofactors that interact with a-tubulin after its CCT-assisted folding (Tian et al, 1997), and TBCB has recently been shown to interact directly with CCT (Carranza et al, 2013). The TBCs are considered central factors in tubulin proteostasis because of their unique intrinsic ability to dissociate tubulin dimers (Lopez-Fanarraga et al, 2001).…”

Section: Introductionmentioning

confidence: 99%

“…TBCB overexpression also interferes with the MT network, although less efficiently (Carranza et al, 2013). The TBCs are necessary for tubulin dimer dissociation and have an important role in regulation of MT plasticity and composition.…”

Section: Introductionmentioning

confidence: 99%

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The structure of the TBCE/TBCB chaperones and α-tubulin complex shows a tubulin dimer dissociation mechanism

Serna

Carranza

Martín‐Benito

et al. 2015

Journal of Cell Science

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BSTRACTTubulin proteostasis is regulated by a group of molecular chaperones termed tubulin cofactors (TBC). Whereas tubulin heterodimer formation is well-characterized biochemically, its dissociation pathway is not clearly understood. Here, we carried out biochemical assays to dissect the role of the human TBCE and TBCB chaperones in a-tubulin-b-tubulin dissociation. We used electron microscopy and image processing to determine the threedimensional structure of the human TBCE, TBCB and a-tubulin (aEB) complex, which is formed upon a-tubulin-b-tubulin heterodimer dissociation by the two chaperones. Docking the atomic structures of domains of these proteins, including the TBCE UBL domain, as we determined by X-ray crystallography, allowed description of the molecular architecture of the aEB complex. We found that heterodimer dissociation is an energy-independent process that takes place through a disruption of the a-tubulin-b-tubulin interface that is caused by a steric interaction between b-tubulin and the TBCE cytoskeleton-associated protein glycine-rich (CAP-Gly) and leucinerich repeat (LRR) domains. The protruding arrangement of chaperone ubiquitin-like (UBL) domains in the aEB complex suggests that there is a direct interaction of this complex with the proteasome, thus mediating a-tubulin degradation.

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Section: Discussionmentioning

confidence: 98%

Section: Characterization Of A-tubulin-b-tubulin Dissociation By Tbcementioning

confidence: 99%

Section: Structure Of the Human Tbce Ubl Domainmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

The structure of the TBCE/TBCB chaperones and α-tubulin complex shows a tubulin dimer dissociation mechanism

Serna

Carranza

Martín‐Benito

et al. 2015

Journal of Cell Science

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Tubulin Folding and Degradation

Serna

Zabala

2016

Encyclopedia of Life Sciences

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Synthesis of polypeptides inside a cell is an astonishing, complex and very efficient process. To reach the active state, proteins will have to face many different problems that in part are solved by molecular chaperones. Tubulins belong to one of the largest superfamilies of proteins with six conserved members. Different members have different roles although they share a general fold. Tubulins reach their final structure in an intricate pathway where different molecular chaperones are involved. Prefoldin and cytosolic chaperonin containing TCP1/TriC are required in the first part of the pathway, while tubulin folding cofactors (TBCs) are involved in the formation of the α‐ and β‐tubulin heterodimers. Later, their role in tubulin proteostasis as well as their implications in different neurodevelopmental disorders has been documented. Key Concepts Tubulins represent one of the largest families of genes and proteins. α‐ and β‐Tubulin heterodimers constitute the structural and functional subunit of microtubules (MTs). Folding of tubulins follows a sophisticated pathway involving several molecular chaperones. Formation of the αβ‐tubulin heterodimer is an extremely regulated process for it is involved in different lateral and longitudinal as well as microtubule associated proteins (MAPs) interactions. TBCs are molecular chaperones specifically required for αβ‐tubulin dimer formation. TBCs are shown to be involved in the release of tubulin monomers from the chaperonin during the folding pathway. The dissociation constant for the tubulin heterodimer has shown to be 10 −11 M and TBCs are required for an efficient tubulin dimer dissociation. TBCs are involved in tubulin proteostasis through dimer dissociation and tagging for proteasome recognition. The first 3D structure of a complex formed between α‐tubulin and two chaperones involved in the tubulin turnover cycle has been established. Genetic defects on TBCs are responsible of neurodevelopmental diseases.

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Characterization of a novel EB1 acetylation site important for the regulation of microtubule dynamics and cargo recruitment

Xie

Yang

Lin

et al. 2017

Journal Cellular Physiology

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Microtubule plus ends undergo highly dynamic modifications to regulate different aspects of cellular activities. Most microtubule plus-end tracking proteins (+TIPs) are recruited to the microtubule ends by the master loading factor, end-binding protein 1 (EB1). These proteins coordinately regulate microtubule dynamics and cellular plasticity. Acetylation is known to modulate EB1 function; however, the molecular details of EB1 acetylation remain largely unclear. We mapped the acetylation pattern of EB1 and identified several previously uncharacterized sites of EB1 acetylation. We examined the effects of lysine-212 (K212) acetylation and found that acetylation of this site accelerates autophagy-mediated EB1 degradation. By time-lapse microscopy, we found that the acetylation-deficient K212R mutant increased the percentage of fast-growing and long-lived microtubules. Although K212 acetylation did not affect microtubule stability in vitro and the association of EB1 with microtubules, the K212R mutant significantly promoted microtubule regrowth in cells. Coimmunoprecipitation assays further revealed that the K212 site was critical for the recruitment of different +TIP cargoes. These data thus uncover a critical role for a novel EB1 acetylation site in regulating the dynamic structure of microtubules.

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Autoinhibition of TBCB regulates EB1-mediated microtubule dynamics

Cited by 21 publications

References 42 publications

The structure of the TBCE/TBCB chaperones and α-tubulin complex shows a tubulin dimer dissociation mechanism

The structure of the TBCE/TBCB chaperones and α-tubulin complex shows a tubulin dimer dissociation mechanism

Tubulin Folding and Degradation

Characterization of a novel EB1 acetylation site important for the regulation of microtubule dynamics and cargo recruitment

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