scholarly journals Structure and function of accessory Sec proteins involved in the adhesin export pathway of Streptococcus gordonii

2017 ◽  
Author(s):  
Yu Chen ◽  
Barbara A. Bensing ◽  
Ravin Seepersaud ◽  
Wei Mi ◽  
Maofu Liao ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Pathogenic Bacteria ◽  
Structure And Function ◽  
Host Cells ◽  
Carbohydrate Binding ◽  
Streptococcus Gordonii ◽  
Carbohydrate Binding Proteins ◽  
Sec Proteins ◽  
And Function ◽  
Complex Crystal

ABSTRACTMany pathogenic bacteria, including Streptococcus gordonii, possess a pathway for the export of a single serine-rich-repeat protein that mediates the adhesion of bacteria to host cells and the extracellular matrix. These adhesins are O-glycosylated by several cytosolic glycosyltransferases and require three accessory Sec proteins (Asp1-3) for export, but how the adhesins are processed for secretion is not well defined. Here, we show that O-glycosylation of S. gordonii adhesin GspB occurs in a sequential manner by three enzymes (GtfA/B, Nss, Gly) that attach N-acetylglucosamine and glucose to Ser/Thr residues. The modified substrate is subsequently transferred from the last glycosyltransferase to the Asp1/2/3 complex. Crystal structures show that both Asp1 and Asp3 are related to carbohydrate binding proteins. Asp1 also has an affinity for phospholipids, which is attenuated by Asp2. These results suggest a mechanism for the modification of adhesin in the cytosol and its subsequent targeting to the export machinery.

Enhanced Structure and Function of Stem Cell-Derived Beta-Like Cells Cultured on Extracellular Matrix

2020 ◽  
Author(s):  
Reena Singh ◽  
Richard Tan ◽  
Clara Tran ◽  
Thomas Loudovaris ◽  
Helen E. Thomas ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Stem Cell ◽  
Structure And Function ◽  
And Function ◽  
Cells Cultured

scholarly journals Breast cancer cell cyclooxygenase-2 expression alters extracellular matrix structure and function and numbers of cancer associated fibroblasts

Oncotarget ◽  
2017 ◽  
Vol 8 (11) ◽  
pp. 17981-17994 ◽  
Author(s):  
Balaji Krishnamachary ◽  
Ioannis Stasinopoulos ◽  
Samata Kakkad ◽  
Marie-France Penet ◽  
Desmond Jacob ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Extracellular Matrix ◽  
Cancer Cell ◽  
Breast Cancer Cell ◽  
Structure And Function ◽  
Cyclooxygenase 2 ◽  
Cancer Associated Fibroblasts ◽  
Matrix Structure ◽  
And Function

Inhibition of sperm-egg fusion in the hamster and mouse by carbohydrates

Zygote ◽  
1994 ◽  
Vol 2 (3) ◽  
pp. 253-262 ◽  
Author(s):  
Ruben H. Ponce ◽  
Umbert A. Urch ◽  
Ryuzo Yanagimachi
Keyword(s):  
Extracellular Matrix ◽  
Plasma Membrane ◽  
Zona Pellucida ◽  
Binding Proteins ◽  
Toxic Effects ◽  
Carbohydrate Binding ◽  
Dextran Sulphate ◽  
Membrane Glycoproteins ◽  
Carbohydrate Binding Proteins

SummaryAfter spermatozoa bind to and penetrate the extracellular matrix of the egg, the zona pellucida, they adhere to and fuse with the plasma membrane of the egg. Since sperm–egg fusion may involve membrane glycoproteins and/or carbohydrate binding proteins, we sought to test this hypothesis by challenging sperm–egg fusion in hamster and in mouse with added carbohydrates. In this study, a number of carbohydrate and glycoconjugates were examined for their ability to inhibit sperm–eggfusion. In the hamster, D(+)-glucosamine, D(+)-galactosamine, albumin-bovine-glucosamide and-galactosamide, fucoidan and dextran sulphate inhibited the fusion of spermatozoa with zona-free eggs. The same effects were seen in the mouse, except for the toxic effects of D(+)-galactosamine. These facts suggest a role of carbohydrate binding proteins or glycoproteins in the fertilisation process at the level of binding to and fusing with the oolemma.

scholarly journals Structure and function of minor pilins of type IV pili

2019 ◽  
Vol 209 (3) ◽  
pp. 301-308 ◽  
Author(s):  
Theis Jacobsen ◽  
Benjamin Bardiaux ◽  
Olivera Francetic ◽  
Nadia Izadi-Pruneyre ◽  
Michael Nilges
Keyword(s):  
Pathogenic Bacteria ◽  
Type Iv Pili ◽  
Host Cells ◽  
Type Ii Secretion ◽  
Type Iv Pilus ◽  
Type Iv ◽  
Flexible Fibers ◽  
Multiple Copies ◽  
Species Specific ◽  
And Function

AbstractType IV pili are versatile and highly flexible fibers formed on the surface of many Gram-negative and Gram-positive bacteria. Virulence and infection rate of several pathogenic bacteria, such as Neisseria meningitidis and Pseudomonas aeruginosa, are strongly dependent on the presence of pili as they facilitate the adhesion of the bacteria to the host cell. Disruption of the interactions between the pili and the host cells by targeting proteins involved in this interaction could, therefore, be a treatment strategy. A type IV pilus is primarily composed of multiple copies of protein subunits called major pilins. Additional proteins, called minor pilins, are present in lower abundance, but are essential for the assembly of the pilus or for its specific functions. One class of minor pilins is required to initiate the formation of pili, and may form a complex similar to that identified in the related type II secretion system. Other, species-specific minor pilins in the type IV pilus system have been shown to promote additional functions such as DNA binding, aggregation and adherence. Here, we will review the structure and the function of the minor pilins from type IV pili.

scholarly journals MT1-MMP–Dependent Remodeling of Cardiac Extracellular Matrix Structure and Function Following Myocardial Infarction

2012 ◽  
Vol 180 (5) ◽  
pp. 1863-1878 ◽  
Author(s):  
Gerald C. Koenig ◽  
R. Grant Rowe ◽  
Sharlene M. Day ◽  
Farideh Sabeh ◽  
Jeffrey J. Atkinson ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Extracellular Matrix ◽  
Structure And Function ◽  
Matrix Structure ◽  
And Function

scholarly journals Cytoskeleton and Adhesion in Myogenesis

2014 ◽  
Vol 2014 ◽  
pp. 1-15 ◽  
Author(s):  
Manoel Luís Costa
Keyword(s):  
Skeletal Muscle ◽  
Extracellular Matrix ◽  
Smooth Muscle ◽  
Muscle Function ◽  
Force Production ◽  
Structure And Function ◽  
Cytoskeletal Proteins ◽  
Skeletal Muscle Differentiation ◽  
And Function ◽  
Structural Adaptations

The function of muscle is to contract, which means to exert force on a substrate. The adaptations required for skeletal muscle differentiation, from a prototypic cell, involve specialization of housekeeping cytoskeletal contracting and supporting systems into crystalline arrays of proteins. Here I discuss the changes that all three cytoskeletal systems (microfilaments, intermediate filaments, and microtubules) undergo through myogenesis. I also discuss their interaction, through the membrane, to extracellular matrix and to other cells, where force will be exerted during contraction. The three cytoskeletal systems are necessary for the muscle cell and must exert complementary roles in the cell. Muscle is a responsive system, where structure and function are integrated: the structural adaptations it undergoes depend on force production. In this way, the muscle cytoskeleton is a portrait of its physiology. I review the cytoskeletal proteins and structures involved in muscle function and focus particularly on their role in myogenesis, the process by which this incredible muscle machine is made. Although the focus is on skeletal muscle, some of the discussion is applicable to cardiac and smooth muscle.

scholarly journals The Structure and Function of Serum Opacity Factor: A Unique Streptococcal Virulence Determinant That Targets High-Density Lipoproteins

2010 ◽  
Vol 2010 ◽  
pp. 1-16 ◽  
Author(s):  
Harry S. Courtney ◽  
Henry J. Pownall
Keyword(s):  
Lipid Vesicles ◽  
Structure And Function ◽  
High Density ◽  
Host Cells ◽  
High Density Lipoproteins ◽  
Multifunctional Protein ◽  
Virulence Determinant ◽  
Serum Opacity Factor ◽  
Animal Pathogens ◽  
And Function

Serum opacity factor (SOF) is a virulence determinant expressed by a variety of streptococcal and staphylococcal species including both human and animal pathogens. SOF derives its name from its ability to opacify serum where it targets and disrupts the structure of high-density lipoproteins resulting in formation of large lipid vesicles that cause the serum to become cloudy. SOF is a multifunctional protein and in addition to its opacification activity, it binds to a number of host proteins that mediate adhesion of streptococci to host cells, and it plays a role in resistance to phagocytosis in human blood. This article will provide an overview of the structure and function of SOF, its role in the pathogenesis of streptococcal infections, its vaccine potential, its prevalence and distribution in bacteria, and the molecular mechanism whereby SOF opacifies serum and how an understanding of this mechanism may lead to therapies for reducing high-cholesterol concentrations in blood, a major risk factor for cardiovascular disease.

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