Clathrin self-assembly is mediated by a tandemly repeated superhelix

Ybe, Joel A.; Brodsky, Frances M.; Hofmann, Kay; Lin, Kai; Liu, Shuhui; Chen, Lin; Earnest, Thomas; Fletterick, Robert J.; Hwang, Peter K.

doi:10.1038/20708

Cited by 137 publications

(161 citation statements)

References 28 publications

(15 reference statements)

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“…As CHC has seven repeat structures (called clathrin repeats) in the middle and C-terminal parts and the predicted tertiary structure of these regions has been reported (Ybe et al, 1999), we constructed various CHC mutants bearing the N-terminal deletion to repeat 1 (aa 686-1675), repeat 2 (aa 833-1675) and repeat 3 (aa 979-1675) to assess which repeat structures are required for binding to p53 (Figure 1d). Analysis of GST pull-down assays revealed that CHC833-1675 had similar p53-binding affinity to wild-type CHC and that further deletion to repeat 3 greatly reduced interaction with p53 ( Figure 1e).…”

Section: Resultsmentioning

confidence: 99%

Monomeric but not trimeric clathrin heavy chain regulates p53-mediated transcription

et al. 2007

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Section: Resultsmentioning

confidence: 99%

Monomeric but not trimeric clathrin heavy chain regulates p53-mediated transcription

et al. 2007

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“…The 192 coordinates of this structure located the centers of contiguous 3.0 nm beads, with these centers being, on average, 0.76 ± 0.10 nm apart. The bead diameter was chosen to equal the average leg thickness of 3.0 nm, determined from the partial crystal structure for the clathrin proximal leg 4 (17). This model was then completed by the addition of 5.0 nm beads to the ends of the legs to account for unresolved terminal domains, in accordance with another partial crystal structure 5 (18).…”

Section: Light Scatteringmentioning

confidence: 99%

“…Each leg was given a length of 52 nm, in correspondence with measurements made from transmission electron microscopy (TEM) images of clathrin (20)(21)(22). To model the solution structures for a comparison with DLS data, here, also, a bead diameter of 3.0 nm, derived from the partial crystal structure for the clathrin proximal leg 6 (17), was augmented by an additional 0.6 nm to approximate the effect of a layer of bound water needed when calculating R H . Thus, 16 beads (total diameter of 3.6 nm) were used, with centers spaced 3.0 nm apart.…”

Section: Modelingmentioning

confidence: 99%

Conformation of a Clathrin Triskelion in Solution

et al. 2006

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A principal component in the protein coats of certain post-golgi and endocytic vesicles is clathrin, which appears as a three-legged heteropolymer (known as a triskelion) that assembles into polyhedral cages principally made up of pentagonal and hexagonal faces. In vitro, this assembly depends upon the pH, with cages forming more readily at low pH and less readily at high pH. We have developed procedures, on the basis of static and dynamic light scattering, to determine the radius of gyration, R g , and hydrodynamic radius, R H , of isolated triskelia, under conditions where cage assembly occurs. Calculations based on rigid molecular bead models of a triskelion show that the measured values can be accounted for by bending the legs and a puckering at the vertex. We also show that the values of R g and R H measured for clathrin triskelia in solution are qualitatively consistent with the conformation of a triskelion in a "D 6 barrel" cage assembly measured by cryoelectron microscopy.A major component of the protein coats of certain endocytic vesicles is clathrin, a heteropolymer composed of a 192 kDa heavy chain and a variable, ca. 23-27 kDa, associated light chain (1). Three clathrin molecules join at a common hub to form a threelegged "triskelion", which is the basic building block of the coats. Each leg is approximately 3.0 nm thick and 52.0 nm in length and ends in a globular "terminal domain" of radius 5.0 nm. By convention, a leg is divided into a proximal segment adjoining the central hub, a linker region, and a distal segment that connects with the terminal domain. A clathrin heavy chain runs the entire length of the leg, with a light chain attached near the common hub (see Figure 1). In vitro, the triskelia assemble into polyhedral cages (or "baskets") composed of pentagonal and hexagonal faces (2), mimicking the structures seen on the outside of endocytic vesicles. One can dissociate baskets or uncoat vesicles by changing the properties † This work was supported by extramural grants from the National Institutes of Health and intramural funds from the National Institute HHS Public Access Author Manuscript Author ManuscriptAuthor ManuscriptAuthor Manuscript of the solution in which they are suspended (e.g., by changing pH and ionic strength) (3) or by adding an uncoating ATPase (4).Triskelia assemble at low pH to form baskets (3) or at higher pH, when clathrin assembly proteins (e.g., AP-2, AP-180, etc.) are added (5). It is not currently known why these conditions favor assembly. Possible mechanisms supporting assembly at low pH include conformational changes in the tertiary structure of the triskelia, which might relieve steric hindrances to basket assembly, and enhanced interactions between the intertwined triskelia that form the basket struts. The role of APs as assembly proteins may be to increase mechanical linkages between the triskelia (5-7).In this paper, we report light-scattering measurements on clathrin in solution, including conditions where assembly occurs. From static light scatteri...

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“…Models for the transient release of calcium have been developed on the basis of several published experimental studies. 39,59 We work under the hypothesis that the signal transduction in the endocytosis pathway is coupled to membrane deformation via two functional interactions: (1) the direct induction of curvature via the interaction of the membrane lipids with epsin; 24,50,56,62 and (2) through the assembly of the clathrin coat, 56,73 which is triggered by an increase in the local concentration of Ca 2+ ions released in the PLCc pathway. 4 In the latter case, above a threshold value of Ca 2+ concentration the clathrin monomers spontaneously self-assemble to form a lattice.…”

Section: Endocytotic Vesicle Nucleationmentioning

confidence: 99%

“…4 In the latter case, above a threshold value of Ca 2+ concentration the clathrin monomers spontaneously self-assemble to form a lattice. 56,73 This leads to the following mechanism for endocytosis. The transient increase in calcium concentration at the site of the activated receptor helps promote clathrin polymerization and coat assembly.…”

Section: Endocytotic Vesicle Nucleationmentioning

confidence: 99%

A Multiscale Computational Approach to Dissect Early Events in the Erb Family Receptor Mediated Activation, Differential Signaling, and Relevance to Oncogenic Transformations

et al. 2007

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Abstract-We describe a hierarchical multiscale computational approach based on molecular dynamics simulations, free energy-based molecular docking simulations, deterministic network-based kinetic modeling, and hybrid discrete/ continuum stochastic dynamics protocols to study the dimermediated receptor activation characteristics of the Erb family receptors, specifically the epidermal growth factor receptor (EGFR). Through these modeling approaches, we are able to extend the prior modeling of EGF-mediated signal transduction by considering specific EGFR tyrosine kinase (EGFRTK) docking interactions mediated by differential binding and phosphorylation of different C-terminal peptide tyrosines on the RTK tail. By modeling signal flows through branching pathways of the EGFRTK resolved on a molecular basis, we are able to transcribe the effects of molecular alterations in the receptor (e.g., mutant forms of the receptor) to differing kinetic behavior and downstream signaling response. Our molecular dynamics simulations show that the drug sensitizing mutation (L834R) of EGFR stabilizes the active conformation to make the system constitutively active. Docking simulations show preferential characteristics (for wildtype vs. mutant receptors) in inhibitor binding as well as preferential enhancement of phosphorylation of particular substrate tyrosines over others. We find that in comparison to the wildtype system, the L834R mutant RTK preferentially binds the inhibitor erlotinib, as well as preferentially phosphorylates the substrate tyrosine Y1068 but not Y1173. We predict that these molecular level changes result in preferential activation of the Akt signaling pathway in comparison to the Erk signaling pathway for cells with normal EGFR expression. For cells with EGFR over expression, the mutant over activates both Erk and Akt pathways, in comparison to wildtype. These results are consistent with qualitative experimental measurements reported in the literature. We discuss these consequences in light of how the network topology and signaling characteristics of altered (mutant) cell lines are shaped differently in relationship to native cell lines.

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Clathrin self-assembly is mediated by a tandemly repeated superhelix

Cited by 137 publications

References 28 publications

Monomeric but not trimeric clathrin heavy chain regulates p53-mediated transcription

Monomeric but not trimeric clathrin heavy chain regulates p53-mediated transcription

Conformation of a Clathrin Triskelion in Solution

A Multiscale Computational Approach to Dissect Early Events in the Erb Family Receptor Mediated Activation, Differential Signaling, and Relevance to Oncogenic Transformations

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