Strong Growth Polarity of Yeast Prion Fiber Revealed by Single Fiber Imaging

Inoue, Yoshio; Kishimoto, Aiko; Hirao, Jun; Yoshida, Masasuke; Taguchi, Hideki

doi:10.1074/jbc.c100304200

Cited by 63 publications

(64 citation statements)

References 27 publications

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“…With this filter, the FITC-labeled seed fibril was also illuminated slightly. This result suggests that ␣-synuclein could elongate in a bidirectional manner from the seeded nucleus, similar to that of A␤ (48) and islet amyloid peptide (49) but different from that of sup35 (50).…”

Section: Incorporation Of Different Protein Seeds Into the ␣-Synucleinmentioning

confidence: 59%

Amyloid Fibril Formation of α-Synuclein Is Accelerated by Preformed Amyloid Seeds of Other Proteins

Yagi

Kusaka

Hongo

et al. 2005

Journal of Biological Chemistry

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␣-Synuclein is one of the causative proteins of familial Parkinson disease, which is characterized by neuronal inclusions named Lewy bodies. Lewy bodies include not only ␣-synuclein but also aggregates of other proteins. This fact raises a question as to whether the formation of ␣-synuclein amyloid fibrils in Lewy bodies may occur via interaction with fibrils derived from different proteins. To probe this hypothesis, we investigated in vitro fibril formation of human ␣-synuclein in the presence of preformed fibril seeds of various different proteins. We used three proteins, Escherichia coli chaperonin GroES, hen lysozyme, and bovine insulin, all of which have been shown to form amyloid fibrils. Very surprisingly, the formation of ␣-synuclein amyloid fibril was accelerated markedly in the presence of preformed seeds of GroES, lysozyme, and insulin fibrils. The structural characteristics of the natively unfolded state of ␣-synuclein may allow binding to various protein particles, which in turn triggers the formation (extension) of ␣-synuclein amyloid fibrils. This finding is very important for understanding the molecular mechanism of Parkinson disease and also provides interesting implications into the mechanism of transmissible conformational diseases.

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Section: Incorporation Of Different Protein Seeds Into the ␣-Synucleinmentioning

confidence: 59%

Amyloid Fibril Formation of α-Synuclein Is Accelerated by Preformed Amyloid Seeds of Other Proteins

Yagi

Kusaka

Hongo

et al. 2005

Journal of Biological Chemistry

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“…For instance, nanofibers are also found in protein amyloid (33)(34)(35)(36)(37)(38)(39)(40)(41)(42)(51)(52)(53)(54)(55). It is possible that some of the selfassembled amyloid nanofibers will undergo reassembly to resist drug and other treatments.…”

Section: Resultsmentioning

confidence: 99%

Dynamic reassembly of peptide RADA16 nanofiber scaffold

Yokoi

Kinoshita

Zhang

2005

Proc. Natl. Acad. Sci. U.S.A.

617

559

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Nanofiber structures of some peptides and proteins as biological materials have been studied extensively, but their molecular mechanism of self-assembly and reassembly still remains unclear. We report here the reassembly of an ionic self-complementary peptide RADARADARADARADA (RADA16-I) that forms a well defined nanofiber scaffold. The 16-residue peptide forms stable ␤-sheet structure and undergoes molecular self-assembly into nanofibers and eventually a scaffold hydrogel consisting of >99.5% water. In this study, the nanofiber scaffold was sonicated into smaller fragments. Circular dichroism, atomic force microscopy, and rheology were used to follow the kinetics of the reassembly. These sonicated fragments not only quickly reassemble into nanofibers that were indistinguishable from the original material, but their reassembly also correlated with the rheological analyses showing an increase of scaffold rigidity as a function of nanofiber length. The disassembly and reassembly processes were repeated four times and, each time, the reassembly reached the original length. We proposed a plausible sliding diffusion model to interpret the reassembly involving complementary nanofiber cohesive ends. This reassembly process is important for fabrication of new scaffolds for 3D cell culture, tissue repair, and regenerative medicine.atomic force microscopy ͉ circular dichroism ͉ dynamic behaviors ͉ ionic self-complementary peptides ͉ nanofiber hydrogels M olecular design, development, and fabrication of biological materials are a prerequisite for the advancement of medical technologies. These include scaffolds for fostering tissue regeneration, tissue engineering in regenerative medicine, and controlled drug release (1-7). Synthetic polymers and biodegradable biomaterials have had a significant impact in medicine over the last two decades (8-10). However, the continuous discovery and design of materials of biological origins are of great interest to multiple and diverse scientific and medical communities. The fabrication of materials at the molecular scale from ''the bottom up,'' one molecule at a time through synthesis and one unit at a time through self-assembly, has many advantages (11,12). This approach is not only flexible and simple, but these materials can be tailor-made, thus facilitating the incorporation of many biochemically and medically desired features.We previously reported the discovery and development of a class of self-assembling peptide scaffold materials to culture cells in three dimensions (13-17). These short, 8-to 16-residue (Ϸ2.5-5 nm in length) peptides are chemically synthesized and form extremely stable ␤-sheet structures in water (13, 14). They not only self-assemble to form stable nanofibers, but also form higher-order nanofiber scaffolds, namely, hydrogels with extremely high water content [Ͼ99.5 (wt͞vol)% water] (15-17). The gelation process is accelerated either by changing to neutral pH or adding physiological concentrations of salt solutions (13-15, 18-21). However, although it has high wat...

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“…No one has yet reported accurate data on the sizes of Sup35p aggregates in a [PSI ϩ ] cell, and, until we know the numbers of pelletable aggregates present (not merely the amount of Sup35p present in such aggregates) and how these numbers relate to Hsp104 activity, we cannot say whether aggregates decline in numbers during growth in the presence of GdnHCl. If such aggregates consist of amyloid fibers and if one or both ends of a fiber provided the template for prionization of native Sup35p molecules (19,35), then the function of Hsp104 might be to cut fibers and create new ends (24), an activity consistent with its known role as a protein "remodeling factor" (17). Whether one or both ends were templates, a single cleavage event would double their numbers and the replication would thus proceed exponentially.…”

Section: Discussionmentioning

confidence: 99%

Guanidine Hydrochloride Inhibits the Generation of Prion “Seeds” but Not Prion Protein Aggregation in Yeast

Ness

Ferreira

Cox

et al. 2002

Molecular and Cellular Biology

179

215

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] by coexpression of a dominant, ATPase-negative allele of HSP104 were similar to those observed for GdnHCl-induced elimination. Based on these and other data, we propose a two-cycle model for "prionization" of Sup35p in [PSI ؉ ] cells: cycle A is the GdnHCl-sensitive (Hsp104-dependent) replication of the prion seeds, while cycle B is a GdnHCl-insensitive (Hsp104-independent) process that converts these seeds to pelletable aggregates.[PSI ϩ ] is a non-Mendelian epigenetic element originally identified in a genetic screen by its ability to increase the efficiency of tRNA-mediated nonsense suppression in Saccharomyces cerevisiae (6, 7). Based on genetic arguments, Wickner (47) was the first to suggest that the [PSI ϩ ] determinant was a self-replicating prion form of translation termination factor Sup35p (also called eRF3 [43,50]). In accordance with Prusiner's original prion hypothesis (33), Sup35p is able to exist in one of two different states: the normal soluble form, required for translation termination, and an "infectious" (i.e., transmissible) aggregated form, i.e., as a prion. ] cells, Sup35p is largely inactivated by its sequestration into high-molecular-weight complexes, thereby precluding it from efficiently performing its role as a translation termination factor.Studies on the conversion of mammalian prion protein PrP to transmissible prion PrP Sc form have generated a number of different models to explain how a prion protein determinant can be propagated and transmitted (see reference 2 for a review). A detailed in vitro analysis of yeast Sup35p self-directed aggregation led Serio et al. (39) to suggest that a process of nucleated conformational conversion of Sup35p most probably occurs in the establishment of the [PSI ϩ ] determinant. This mechanism involves both the nucleated-polymerization and the template assembly processes proposed for PrP (2), and Serio et al. (39) proposed that conformational conversion of the native Sup35p occurs by the seeding activity of a nucleated complex. These nuclei (or intermediate oligomers) would be formed by the conformational modification of the partially unfolded Sup35p protein. Once the intermediate polymers reach a critical concentration, assembly of large polymers can occur through a templating mechanism.Physicochemical analyses of Sup35p have shown that the N-terminal portion of the protein (the so-called N domain or prion-forming domain) contains the minimal region responsible for [PSI ϩ ] propagation in vivo and directs amyloid fiber formation in vitro (16,23,32). The Sup35p amyloid fibers have features in common with the amyloid proteins implicated in several human diseases (for reviews, see references 1, 11, 34, and 48). However, it remains to be established whether the * Corresponding author. Mailing address:

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Strong Growth Polarity of Yeast Prion Fiber Revealed by Single Fiber Imaging

Cited by 63 publications

References 27 publications

Amyloid Fibril Formation of α-Synuclein Is Accelerated by Preformed Amyloid Seeds of Other Proteins

Amyloid Fibril Formation of α-Synuclein Is Accelerated by Preformed Amyloid Seeds of Other Proteins

Dynamic reassembly of peptide RADA16 nanofiber scaffold

Guanidine Hydrochloride Inhibits the Generation of Prion “Seeds” but Not Prion Protein Aggregation in Yeast

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