Dataset Information

Supramolecular Structures of the Dictyostelium Lamin NE81.

ABSTRACT: Nuclear lamins are nucleus-specific intermediate filaments (IF) found at the inner nuclear membrane (INM) of the nuclear envelope (NE). Together with nuclear envelope transmembrane proteins, they form the nuclear lamina and are crucial for gene regulation and mechanical robustness of the nucleus and the whole cell. Recently, we characterized Dictyostelium NE81 as an evolutionarily conserved lamin-like protein, both on the sequence and functional level. Here, we show on the structural level that the Dictyostelium NE81 is also capable of assembling into filaments, just as metazoan lamin filament assemblies. Using field-emission scanning electron microscopy, we show that NE81 expressed in Xenopous oocytes forms filamentous structures with an overall appearance highly reminiscent of Xenopus lamin B2. The in vitro assembly properties of recombinant His-tagged NE81 purified from Dictyostelium extracts are very similar to those of metazoan lamins. Super-resolution stimulated emission depletion (STED) and expansion microscopy (ExM), as well as transmission electron microscopy of negatively stained purified NE81, demonstrated its capability of forming filamentous structures under low-ionic-strength conditions. These results recommend Dictyostelium as a non-mammalian model organism with a well-characterized nuclear envelope involving all relevant protein components known in animal cells.

SUBMITTER: Grafe M

PROVIDER: S-EPMC6406624 | biostudies-literature | 2019 Feb

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Supramolecular Structures of the <i>Dictyostelium</i> Lamin NE81.

Grafe Marianne M Batsios Petros P Meyer Irene I Lisin Daria D Baumann Otto O Goldberg Martin W MW Gräf Ralph R

Cells 20190216 2

Nuclear lamins are nucleus-specific intermediate filaments (IF) found at the inner nuclear membrane (INM) of the nuclear envelope (NE). Together with nuclear envelope transmembrane proteins, they form the nuclear lamina and are crucial for gene regulation and mechanical robustness of the nucleus and the whole cell. Recently, we characterized <i>Dictyostelium</i> NE81 as an evolutionarily conserved lamin-like protein, both on the sequence and functional level. Here, we show on the structural leve ...[more]

PMID: 30781468

Similar Datasets

Project description:The unique physiochemical properties and multiscale organization of layered materials draw the attention of researchers across a wide range of scientific disciplines. Layered structures are commonly found in diverse biological systems where they fulfill various functions. A prominent example of layered biological materials is the organization of proteins and polypeptides into the archetypal aggregated amyloidal structures. While the organization of proteins into amyloid structures was initially associated with various degenerative disorders, it was later revealed that proteins not related to any disease could also form identical layered assemblies. Thus, it appears that the ability of peptides and proteins to produce amyloid-like aggregates represents a generic property of polyamides to assemble into higher order fibrillar structures. In the aggregated state, the peptide backbone forms ?-sheet structures which are further organized into layered arrangements. We have recently extended the identified amyloidogenic building blocks to include not only peptides or proteins, but also single amino acids and other metabolites. High resolution spectroscopy and crystallography analyses confirm the clear potential of amino acids and other metabolites to form layered amyloid-like aggregates showing biophysical and biochemical properties similar to protein amyloids. Therefore, the generic propensity of peptides and proteins backbones to assemble into layered organizations may emanate from their basic building block, the amino acid. In this Account, we aim to introduce the concept of supramolecular ?-sheet organization of single amino acids and to present an analysis of their layered-structure organization based on single crystal structures. We demonstrate that, despite the different side-chains that considerably vary in their chemical properties, all coded amino acids display a layer-like assembly stabilized by ?-amine to ?-carboxyl H-bonds, resembling supramolecular ?-sheet structures, while the side-chains determine the higher order organization of the layers. Our work presents the first analysis of the ?-sheet propensity of single amino acids in their unbound form, indicating an evolutionary predisposition. We classify the amino acids ?-sheet propensity on the basis of the interlayer separation distance in the crystal packing, which correlates well with previously reported classifications based on various criteria, such as hydrophobicity, steric bulkiness, and folding. In addition, we demonstrate that the relative direction of ?-amine to ?-carboxyl H-bonding pattern provides critical insights regarding the stabilization of parallel versus antiparallel ?-sheet structures by the various amino acids. Taken together, our analysis of amino acid crystals provides substantial information regarding protein folding and dynamics and could serve as basic rules set for the design of potential building blocks for molecular self-assembly to produce functional materials of tunable properties, an important objective of bottom-up nanotechnology.

Dataset Information

Supramolecular Structures of the Dictyostelium Lamin NE81.

Publications

Supramolecular Structures of the <i>Dictyostelium</i> Lamin NE81.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets