scholarly journals Axonemal dynein light chain-1 locates at the microtubule-binding domain of the γ heavy chain

2015 ◽  
Vol 26 (23) ◽  
pp. 4236-4247 ◽  
Author(s):  
Muneyoshi Ichikawa ◽  
Kei Saito ◽  
Haru-aki Yanagisawa ◽  
Toshiki Yagi ◽  
Ritsu Kamiya ◽  
...  
Keyword(s):  
Light Chain ◽  
Regulatory Mechanism ◽  
Binding Domain ◽  
Particle Analysis ◽  
Dynein Light Chain ◽  
Microtubule Binding ◽  
Heavy Chains ◽  
Microtubule Binding Domain ◽  
Axonemal Dynein ◽  
Force Generator

The outer arm dynein (OAD) complex is the main propulsive force generator for ciliary/flagellar beating. In Chlamydomonas and Tetrahymena, the OAD complex comprises three heavy chains (α, β, and γ HCs) and >10 smaller subunits. Dynein light chain-1 (LC1) is an essential component of OAD. It is known to associate with the Chlamydomonas γ head domain, but its precise localization within the γ head and regulatory mechanism of the OAD complex remain unclear. Here Ni-NTA-nanogold labeling electron microscopy localized LC1 to the stalk tip of the γ head. Single-particle analysis detected an additional structure, most likely corresponding to LC1, near the microtubule-binding domain (MTBD), located at the stalk tip. Pull-down assays confirmed that LC1 bound specifically to the γ MTBD region. Together with observations that LC1 decreased the affinity of the γ MTBD for microtubules, we present a new model in which LC1 regulates OAD activity by modulating γ MTBD's affinity for the doublet microtubule.

scholarly journals The complex of outer-arm dynein light chain-1 and the microtubule-binding domain of the γ heavy chain shows how axonemal dynein tunes ciliary beating

2020 ◽  
Vol 295 (12) ◽  
pp. 3982-3989 ◽  
Author(s):  
Akiyuki Toda ◽  
Yosuke Nishikawa ◽  
Hideaki Tanaka ◽  
Toshiki Yagi ◽  
Genji Kurisu
Keyword(s):  
Binding Affinity ◽  
Light Chain ◽  
Mutational Analysis ◽  
Molecular Model ◽  
Binding Domain ◽  
Structural Basis ◽  
Dynein Light Chain ◽  
Microtubule Binding ◽  
Microtubule Binding Domain ◽  
Axonemal Dynein

Axonemal dynein is a microtubule-based molecular motor that drives ciliary/flagellar beating in eukaryotes. In axonemal dynein, the outer-arm dynein (OAD) complex, which comprises three heavy chains (α, β, and γ), produces the main driving force for ciliary/flagellar motility. It has recently been shown that axonemal dynein light chain-1 (LC1) binds to the microtubule-binding domain (MTBD) of OADγ, leading to a decrease in its microtubule-binding affinity. However, it remains unclear how LC1 interacts with the MTBD and controls the microtubule-binding affinity of OADγ. Here, we have used X-ray crystallography and pulldown assays to examine the interaction between LC1 and the MTBD, identifying two important sites of interaction in the MTBD. Solving the LC1-MTBD complex from Chlamydomonas reinhardtii at 1.7 Å resolution, we observed that one site is located in the H5 helix and that the other is located in the flap region that is unique to some axonemal dynein MTBDs. Mutational analysis of key residues in these sites indicated that the H5 helix is the main LC1-binding site. We modeled the ternary structure of the LC1-MTBD complex bound to microtubules based on the known dynein-microtubule complex. This enabled us to propose a structural basis for both formations of the ternary LC1-MTBD-microtubule complex and LC1-mediated tuning of MTBD binding to the microtubule, suggesting a molecular model for how axonemal dynein senses the curvature of the axoneme and tunes ciliary/flagellar beating.

scholarly journals Backbone and partial side chain assignment of the microtubule binding domain of the MAP1B light chain

2013 ◽  
Vol 8 (1) ◽  
pp. 123-127 ◽  
Author(s):  
Zsuzsanna Orbán-Németh ◽  
Morkos A. Henen ◽  
Leonhard Geist ◽  
Szymon Żerko ◽  
Saurabh Saxena ◽  
...  
Keyword(s):  
Light Chain ◽  
Binding Domain ◽  
Side Chain ◽  
Microtubule Binding ◽  
Microtubule Binding Domain

scholarly journals Structure and Functional Role of Dynein's Microtubule-Binding Domain

Science ◽  
2008 ◽  
Vol 322 (5908) ◽  
pp. 1691-1695 ◽  
Author(s):  
A. P. Carter ◽  
J. E. Garbarino ◽  
E. M. Wilson-Kubalek ◽  
W. E. Shipley ◽  
C. Cho ◽  
...  
Keyword(s):  
Functional Role ◽  
Binding Domain ◽  
Microtubule Binding ◽  
Microtubule Binding Domain

scholarly journals Autoregulatory control of microtubule binding in doublecortin-like kinase 1

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Regina L Agulto ◽  
Melissa M Rogers ◽  
Tracy C Tan ◽  
Amrita Ramkumar ◽  
Ashlyn M Downing ◽  
...  
Keyword(s):  
Binding Affinity ◽  
Therapeutic Target ◽  
Kinase Activity ◽  
Kinase Inhibitors ◽  
Binding Domain ◽  
Cancer Development ◽  
Microtubule Binding ◽  
Microtubule Binding Domain

The microtubule-associated protein, doublecortin-like kinase 1 (DCLK1), is highly expressed in a range of cancers and is a prominent therapeutic target for kinase inhibitors. The physiological roles of DCLK1 kinase activity and how it is regulated remain elusive. Here, we analyze the role of mammalian DCLK1 kinase activity in regulating microtubule binding. We find that DCLK1 autophosphorylates a residue within its C-terminal tail to restrict its kinase activity and prevent aberrant hyperphosphorylation within its microtubule-binding domain. Removal of the C-terminal tail or mutation of this residue causes an increase in phosphorylation within the doublecortin domains, which abolishes microtubule binding. Therefore, autophosphorylation at specific sites within DCLK1 have diametric effects on the molecule's association with microtubules. Our results suggest a mechanism by which DCLK1 modulates its kinase activity to tune its microtubule-binding affinity. These results provide molecular insights for future therapeutic efforts related to DCLK1's role in cancer development and progression.

The projection domain of MAP2b regulates microtubule protrusion and process formation in Sf9 cells

2002 ◽  
Vol 115 (7) ◽  
pp. 1523-1539 ◽  
Author(s):  
Dave Bélanger ◽  
Carole Abi Farah ◽  
Minh Dang Nguyen ◽  
Michel Lauzon ◽  
Sylvie Cornibert ◽  
...  
Keyword(s):  
Cell Surface ◽  
Binding Domain ◽  
Intramolecular Interactions ◽  
Microtubule Assembly ◽  
Sf9 Cells ◽  
Microtubule Binding ◽  
Process Formation ◽  
Microtubule Binding Domain ◽  
Projection Domain

The expression of microtubule-associated protein 2 (MAP2), developmentally regulated by alternative splicing, coincides with neurite outgrowth. MAP2 proteins contain a microtubule-binding domain (C-terminal) that promotes microtubule assembly and a poorly characterized domain, the projection domain(N-terminal), extending at the surface of microtubules. MAP2b differs from MAP2c by an additional sequence of 1372 amino acids in the projection domain. In this study, we examined the role of the projection domain in the protrusion of microtubules from the cell surface and the subsequent process formation in Sf9 cells. In this system, MAP2b has a lower capacity to induce process formation than MAP2c. To investigate the role of the projection domain in this event, we expressed truncated forms of MAP2b and MAP2c that have partial or complete deletion of their projection domain in Sf9 cells. Our results indicate that process formation is induced by the microtubule-binding domain of these MAP2 proteins and is regulated by their projection domain. Furthermore, the microtubule-binding activity of MAP2b and MAP2c truncated forms as well as the structural properties of the microtubule bundles induced by them do not seem to be the only determinants that control the protrusion of microtubules from the cell surface in Sf9 cells. Rather, our data suggest that microtubule protrusion and process formation are regulated by intramolecular interactions between the projection domain and its microtubule-binding domain in MAP2b.

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