The effect of phalloidin and jasplakinolide on the flexibility and thermal stability of actin filaments

Visegrády, Balázs; Lőrinczy, D.; Hild, Gábor; Somogyi, B; Nyitrai, Miklós

doi:10.1016/j.febslet.2004.03.096

Cited by 68 publications

(58 citation statements)

References 23 publications

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“…JAS markedly inhibited virion infection, whereas actin destabilizers did not. The variable effects of these actin-targeted drugs suggested either that JAS induced a structural barrier to endocytosis through the stabilization of the cortical actin cytoskeleton or that these late endocytic steps required actin filament turnover, which is inhibited by JAS (Bubb et al, 2000;Visegrady et al, 2004) but not always by CD (Cooper, 1987). Our results are consistent with both of these interpretations.…”

Section: The Role(s) Of Actin In Hemoglobin Transportsupporting

confidence: 82%

A new model for hemoglobin ingestion and transport by the human malaria parasite Plasmodium falciparum

Lazarus

Schneider

Taraschi

2008

Journal of Cell Science

108

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The current model for hemoglobin ingestion and transport by intraerythrocytic Plasmodium falciparum malaria parasites shares similarities with endocytosis. However, the model is largely hypothetical, and the mechanisms responsible for the ingestion and transport of host cell hemoglobin to the lysosome-like food vacuole (FV) of the parasite are poorly understood. Because actin dynamics play key roles in vesicle formation and transport in endocytosis, we used the actin-perturbing agents jasplakinolide and cytochalasin D to investigate the role of parasite actin in hemoglobin ingestion and transport to the FV. In addition, we tested the current hemoglobin trafficking model through extensive analysis of serial thin sections of parasitized erythrocytes (PE) by electron microscopy. We find that actin dynamics play multiple, important roles in the hemoglobin transport pathway, and that hemoglobin delivery to the FV via the cytostomes might be required for parasite survival. Evidence is provided for a new model, in which hemoglobin transport to the FV occurs by a vesicle-independent process.

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Section: The Role(s) Of Actin In Hemoglobin Transportsupporting

confidence: 82%

A new model for hemoglobin ingestion and transport by the human malaria parasite Plasmodium falciparum

Lazarus

Schneider

Taraschi

2008

Journal of Cell Science

108

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“…A similar shift in the melting temperature of F-actin was previously observed by Nikolaeva et al [25]. In agreement with previous results the presence of jasplakinolide has shifted the T m to 87.3 °C [10]. We also found that when the jasplakinolide bound to the ADP.BeF x saturated actin filaments the melting temperature shifted to 85.6 °C, i.e.…”

Section: Introductionsupporting

confidence: 81%

“…This toxin can decrease the amount of sequestered actin monomers by lowering the critical concentration of actin and enhances the polymerization of the filaments by accelerating the speed of the nucleation step [13]. Differential scanning calorimetry (DSC) studies revealed that jasplakinolide is able to stabilize actin filaments at sub-stoichiometric concentration as well [10,11].…”

Section: Introductionmentioning

confidence: 99%

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The effect of jasplakinolide on the thermodynamic properties of ADP.BeFx bound actin filaments

et al. 2007

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The effect of BeF x and a natural toxin (jasplakinolide) was examined on the thermal stability of actin filaments by using differential scanning calorimetry. The phosphate analogue beryllium fluoride shifted the melting temperature of actin filaments (67.4 °C) to 83.7 °C indicating that the filaments were thermodynamically more stable in their complex with ADP.BeF x . A similar tendency was observed when the jasplakinolide was used in the absence of BeF x . When both the ADP.BeF x and the jasplakinolide bound to the actin filaments their collective effect was similar to that observed with ADP.BeF x or jasplakinolide alone. These results suggested that ADP.BeF x and jasplakinolide probably stabilize the actin filaments by similar molecular mechanisms.

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“…Previous studies have shown that the binding of phalloidin stabilizes the structure of actin filaments (27)(28)(29)(30)(31)(32)(33) and one bound phalloidin can stabilize seven neighboring protomers (26). In this work, we characterize the effect of phalloidin on the thermal stability of actin filaments in complex with different nucleotide analogues (ADP.BeF x or ADP.AlF 4 ) by using differential scanning calorimetry (DSC).…”

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Noncooperative Stabilization Effect of Phalloidin on ADP.BeF_x- and ADP.AlF₄-Actin Filaments

et al. 2008

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Actin plays important roles in eukaryotic cell motility. During actin polymerization, the actinbound ATP is hydrolyzed to ADP and P i . We carried out differential scanning calorimetry experiments to characterize the cooperativity of the stabilizing effect of phalloidin on actin filaments in their ADP.P i state. The ADP.P i state was mimicked by using ADP.BeF x or ADP.AlF 4 . The results showed that the binding of the nucleotide analogues or phalloidin stabilized the actin filaments to a similar extent when added separately. Phalloidin binding to ADP.BeF x -or ADP.AlF 4 -actin filaments further stabilized them, indicating that the mechanism by which phalloidin and the nucleotide analogues affect the filament structure was different. The results also showed that the stabilization effect of phalloidin binding to ADP.BeF x or ADP.AlF 4 -bound actin filaments was not cooperative. Since the effect of phalloidin binding was cooperative in the absence of these nucleotide analogues, these results suggest that the binding of ADP.BeF x or ADP.AlF 4 to the actin modified the protomer-protomer interactions along the actin filaments.Actin is one of the main components of the cytoskeleton and plays important roles in the motility of eukaryotic cells (1-7). The actin monomer can bind a nucleotide in complex with a divalent cation in the cleft between the two main domains of the protein (Figure 1) (8). During polymerization, the ATP is hydrolyzed to ADP and P i 1 (9-16). The ADP.P i state is transient as the inorganic phosphate product is released from actin after polymerization. For † This study was supported by grants from the Hungarian Scientific Research Fund [OTKA Grants K60186 and K60968 (M.Ny.)]. The SETARAM Micro DSC-II instrument was purchased with a grant MATERIALS AND METHODS ChemicalsKCl, MgCl 2 , CaCl 2 , MOPS, EGTA, AlCl 3 , and NaF were purchased from SIGMA-Aldrich (Budapest, Hungary). ATP, ADP, and β-mercaptoethanol were obtained from MERCK (Darmstadt, Germany). NaN 3 and BeSO 4 were purchased from Fluka (St. Gallen, Switzerland). Protein PreparationSkeletal actin was prepared from acetone powder obtained from rabbit muscle (12,34). After purification, the calcium-bound actin monomers were stored in a 2 mM MOPS buffer (pH 7.3) with 0.2 mM ATP, 0.1 mM CaCl 2 , 0.1 mM β-mercaptoethanol, and 0.005% NaN 3 .The actin monomer concentration was determined by absorption photometry using 0.63 mg −1 mL cm −1 as the extinction coefficient at 290 nm (35). Actin-bound calcium was exchanged for magnesium by incubating the samples with 0.2 mM EGTA and 0.1 mM MgCl 2 for 5 min (36). Actin polymerization was initiated by the addition of 2 mM MgCl 2 and 100 mM KCl. ADP.BeF x -actin filaments were prepared in a similar way as described by Levitsky and colleagues (37); BeSO 4 (0.03-3 mM) and NaF (0.1-10 mM) were added to the samples, and actin was polymerized at room temperature for 3 h. Note that since the presence of ADP, BeSO 4 , and NaF in the solution leads to formation of either ADP.BeF 2 (OH) -•H 2 O or ADP.BeF 3 -...

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The effect of phalloidin and jasplakinolide on the flexibility and thermal stability of actin filaments

Cited by 68 publications

References 23 publications

A new model for hemoglobin ingestion and transport by the human malaria parasite Plasmodium falciparum

A new model for hemoglobin ingestion and transport by the human malaria parasite Plasmodium falciparum

The effect of jasplakinolide on the thermodynamic properties of ADP.BeFx bound actin filaments

Noncooperative Stabilization Effect of Phalloidin on ADP.BeF_x- and ADP.AlF₄-Actin Filaments

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The effect of phalloidin and jasplakinolide on the flexibility and thermal stability of actin filaments

Cited by 68 publications

References 23 publications

A new model for hemoglobin ingestion and transport by the human malaria parasite Plasmodium falciparum

A new model for hemoglobin ingestion and transport by the human malaria parasite Plasmodium falciparum

The effect of jasplakinolide on the thermodynamic properties of ADP.BeFx bound actin filaments

Noncooperative Stabilization Effect of Phalloidin on ADP.BeFx- and ADP.AlF4-Actin Filaments

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Noncooperative Stabilization Effect of Phalloidin on ADP.BeF_x- and ADP.AlF₄-Actin Filaments