scholarly journals The extracellular matrix of Volvox carteri: molecular structure of the cellular compartment.

1989 ◽  
Vol 109 (6) ◽  
pp. 3493-3501 ◽  
Author(s):  
H Ertl ◽  
R Mengele ◽  
S Wenzl ◽  
J Engel ◽  
M Sumper
Keyword(s):  
Extracellular Matrix ◽  
Chemical Structure ◽  
Chemical Nature ◽  
Sulfated Polysaccharide ◽  
Surface Glycoprotein ◽  
Amino Acid Residues ◽  
Volvox Carteri ◽  
Cellular Compartment ◽  
Cross Links ◽  
Cellular Compartments

The extracellular matrix (ECM) of Volvox contains insoluble fibrous layers that surround individual cells at a distance to form contiguous cellular compartments. Using immunological techniques, we identified a sulfated surface glycoprotein (SSG 185) as the monomeric precursor of this substructure within the ECM. The primary structure of the SSG 185 poly-peptide chain has been derived from cDNA and genomic DNA. A central domain of the protein, 80 amino acid residues long, consists almost exclusively of hydroxyproline residues. The chemical structure of the highly sulfated polysaccharide covalently attached to SSG 185 has been determined by permethylation analysis. As revealed by EM, SSG 185 is a rod-shaped molecule with a 21-nm-long polysaccharide strand protruding from its central region. The chemical nature of the cross-links between SSG 185 monomers is discussed.

scholarly journals Mapping the Contact Sites of the Escherichia coli Division-Initiating Proteins FtsZ and ZapA by BAMG Cross-Linking and Site-Directed Mutagenesis

2018 ◽  
Vol 19 (10) ◽  
pp. 2928 ◽  
Author(s):  
Winfried Roseboom ◽  
Madhvi Nazir ◽  
Nils Meiresonne ◽  
Tamimount Mohammadi ◽  
Jolanda Verheul ◽  
...  
Keyword(s):  
Site Directed Mutagenesis ◽  
Cross Linking ◽  
Directed Mutagenesis ◽  
Amino Acid Residues ◽  
Binding Interface ◽  
Tetrameric Structure ◽  
Z Ring ◽  
Cross Links ◽  
Chemical Cross Linking

Cell division in bacteria is initiated by the polymerization of FtsZ at midcell in a ring-like structure called the Z-ring. ZapA and other proteins assist Z-ring formation and ZapA binds ZapB, which senses the presence of the nucleoids. The FtsZ–ZapA binding interface was analyzed by chemical cross-linking mass spectrometry (CXMS) under in vitro FtsZ-polymerizing conditions in the presence of GTP. Amino acids residue K42 from ZapA was cross-linked to amino acid residues K51 and K66 from FtsZ, close to the interphase between FtsZ molecules in protofilaments. Five different cross-links confirmed the tetrameric structure of ZapA. A number of FtsZ cross-links suggests that its C-terminal domain of 55 residues, thought to be largely disordered, has a limited freedom to move in space. Site-directed mutagenesis of ZapA reveals an interaction site in the globular head of the protein close to K42. Using the information on the cross-links and the mutants that lost the ability to interact with FtsZ, a model of the FtsZ protofilament–ZapA tetramer complex was obtained by information-driven docking with the HADDOCK2.2 webserver.

Lysyl oxidases: from enzyme activity to extracellular matrix cross-links

2019 ◽  
Vol 63 (3) ◽  
pp. 349-364 ◽  
Author(s):  
Sylvain D. Vallet ◽  
Sylvie Ricard-Blum
Keyword(s):  
Extracellular Matrix ◽  
Molecular Mechanisms ◽  
Catalytic Domain ◽  
Lysyl Oxidase ◽  
Dimensional Structure ◽  
Cross Linking ◽  
Copper Binding ◽  
Molecular Features ◽  
Ecm Proteins ◽  
Cross Links

Abstract The lysyl oxidase family comprises five members in mammals, lysyl oxidase (LOX) and four lysyl oxidase like proteins (LOXL1-4). They are copper amine oxidases with a highly conserved catalytic domain, a lysine tyrosylquinone cofactor, and a conserved copper-binding site. They catalyze the first step of the covalent cross-linking of the extracellular matrix (ECM) proteins collagens and elastin, which contribute to ECM stiffness and mechanical properties. The role of LOX and LOXL2 in fibrosis, tumorigenesis, and metastasis, including changes in their expression level and their regulation of cell signaling pathways, have been extensively reviewed, and both enzymes have been identified as therapeutic targets. We review here the molecular features and three-dimensional structure/models of LOX and LOXLs, their role in ECM cross-linking, and the regulation of their cross-linking activity by ECM proteins, proteoglycans, and by inhibitors. We also make an overview of the major ECM cross-links, because they are the ultimate molecular readouts of LOX/LOXL activity in tissues. The recent 3D model of LOX, which recapitulates its known structural and biochemical features, will be useful to decipher the molecular mechanisms of LOX interaction with its various substrates, and to design substrate-specific inhibitors, which are potential antifibrotic and antitumor drugs.

scholarly journals A polymorphic, prespore-specific cell surface glycoprotein is present in the extracellular matrix of Dictyostelium discoideum.

1985 ◽  
Vol 5 (10) ◽  
pp. 2559-2566 ◽  
Author(s):  
W N Grant ◽  
D L Welker ◽  
K L Williams
Keyword(s):  
Extracellular Matrix ◽  
Cell Surface ◽  
Dictyostelium Discoideum ◽  
Genetic Relationships ◽  
Specific Protein ◽  
Surface Glycoprotein ◽  
Specific Cell ◽  
Developmentally Regulated ◽  
Cell Surface Glycoprotein ◽  
Specific Cell Surface

Polymorphisms of a major developmentally regulated prespore-specific protein (PsA) in Dictyostelium discoideum slugs are described. These polymorphisms allowed discrimination between PsA (found on the cell surface and in the extracellular matrix) and a similar extracellular but nonpolymorphic protein, ShA. The two proteins were also distinguished by their differing reactivities with a range of monoclonal antibodies and by their sensitivity to release from the sheath with cellulase. The results are discussed in terms of the molecular and genetic relationships between the cell surface and the extracellular matrix during development.

scholarly journals Cross-linking reveals laminin coiled-coil architecture

2016 ◽  
Vol 113 (47) ◽  
pp. 13384-13389 ◽  
Author(s):  
Gad Armony ◽  
Etai Jacob ◽  
Toot Moran ◽  
Yishai Levin ◽  
Tevie Mehlman ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Self Assembly ◽  
Quaternary Structure ◽  
Coiled Coil ◽  
Surface Proteins ◽  
Cross Linking ◽  
Single Particle Reconstruction ◽  
Cross Links ◽  
Particle Reconstruction ◽  
Key Questions

Laminin, an ∼800-kDa heterotrimeric protein, is a major functional component of the extracellular matrix, contributing to tissue development and maintenance. The unique architecture of laminin is not currently amenable to determination at high resolution, as its flexible and narrow segments complicate both crystallization and single-particle reconstruction by electron microscopy. Therefore, we used cross-linking and MS, evaluated using computational methods, to address key questions regarding laminin quaternary structure. This approach was particularly well suited to the ∼750-Å coiled coil that mediates trimer assembly, and our results support revision of the subunit order typically presented in laminin schematics. Furthermore, information on the subunit register in the coiled coil and cross-links to downstream domains provide insights into the self-assembly required for interaction with other extracellular matrix and cell surface proteins.

Cervical Collagen Network Remodeling in Normal and Disrupted Parturition Mouse Models

2013 ◽  
Author(s):  
Kyoko Yoshida ◽  
Claire Reeves ◽  
MiJung Kim ◽  
Jan Kitajewski ◽  
Joy Vink ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Post Partum ◽  
Late Pregnancy ◽  
Material Strength ◽  
Collagen Network ◽  
Fixed Charge Density ◽  
Cross Links ◽  
Three Stages ◽  
Mechanical Barrier ◽  
In Pregnancy

The cervix plays an important role in pregnancy as a mechanical barrier to prevent preterm birth (PTB). The material strength of the cervix can be attributed to its extracellular matrix (ECM), a network of cross-linked collagens (types I and III) embedded within a viscous matrix of glycosaminoglycans (GAG). GAGs are negatively charged polysaccharides that provide a fixed charge density (FCD) within the tissue to maintain hydration. Throughout gestation, the ECM of the cervix undergoes a remodeling process characterized by three stages: gradual softening in early pregnancy, a rapid increase in tissue distensibility termed ripening in late pregnancy, and repair at post partum 1. As the cervix softens and ripens, mature collagen cross-links break down while GAG content increases 2,3. Previous research has shown that these changes in collagen and GAGs correlate to a mechanically softer cervix at term 4.

Chemical structure, anti-inflammatory and antinociceptive activities of a sulfated polysaccharide from Gracilaria intermedia algae

2020 ◽  
Vol 159 ◽  
pp. 966-975 ◽  
Author(s):  
Luís Eduardo C. Costa ◽  
Tarcisio Vieira Brito ◽  
Renan O. Silva Damasceno ◽  
Willer M. Sousa ◽  
Francisco Clark N. Barros ◽  
...  
Keyword(s):  
Chemical Structure ◽  
Sulfated Polysaccharide ◽  
Anti Inflammatory

scholarly journals A novel extensin that may organize extracellular matrix biogenesis in Volvox carteri.

1992 ◽  
Vol 11 (6) ◽  
pp. 2055-2062 ◽  
Author(s):  
H. Ertl ◽  
A. Hallmann ◽  
S. Wenzl ◽  
M. Sumper
Keyword(s):  
Extracellular Matrix ◽  
Volvox Carteri

scholarly journals Sexual Pheromone Induces Diffusion of the Pheromone-Homologous Polypeptide in the Extracellular Matrix of Volvox carteri

2007 ◽  
Vol 6 (11) ◽  
pp. 2157-2162 ◽  
Author(s):  
Koichi Ishida
Keyword(s):  
Extracellular Matrix ◽  
Green Fluorescent Protein ◽  
Fluorescent Protein ◽  
Sexual Pheromone ◽  
Volvox Carteri ◽  
Terminal Domain ◽  
Induction Signal ◽  
C Terminus ◽  
Green Fluorescent

ABSTRACT The C-terminal domain of pherophorin II is homologous to the sexual pheromone of Volvox carteri and is released from other domains during sexual induction. Green fluorescent protein fused to the C terminus of pherophorin II was located at the extracellular matrix directly surrounding the gonidium, the final target of the sexual-induction signal.

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