scholarly journals Mutually Exclusive Distribution of the Focal Adhesion Associated Proteins and the Erythrocyte Membrane Skeleton Proteins in the Human Fibroblast Plasma Membrane Undercoat.

1996 ◽  
Vol 21 (1) ◽  
pp. 27-39 ◽  
Author(s):  
Kazuo Katoh ◽  
Yumiko Kano ◽  
Michitaka Masuda ◽  
Keigi Fujiwara
Keyword(s):  
Plasma Membrane ◽  
Erythrocyte Membrane ◽  
Focal Adhesion ◽  
Human Fibroblast ◽  
Membrane Skeleton ◽  
Associated Proteins

Change in distribution of cytoskeleton-associated proteins, lasp-1 and palladin, during uterine receptivity in the rat endometrium

2018 ◽  
Vol 30 (11) ◽  
pp. 1482 ◽  
Author(s):  
Leigh Nicholson ◽  
Laura Lindsay ◽  
Christopher R. Murphy
Keyword(s):  
Plasma Membrane ◽  
Focal Adhesion ◽  
Early Pregnancy ◽  
Morphological Changes ◽  
Cytoskeletal Proteins ◽  
Initial Contact ◽  
Luminal Epithelium ◽  
Uterine Receptivity ◽  
Uterine Lumen ◽  
Associated Proteins

The epithelium of the uterine lumen is the first point of contact with the blastocyst before implantation. To facilitate pregnancy, these uterine epithelial cells (UECs) undergo morphological changes specific to the receptive uterus. These changes include basal, lateral and apical alterations in the plasma membrane of UECs. This study looked at the cytoskeletal and focal adhesion-associated proteins, lasp-1 and palladin, in the uterus during early pregnancy in the rat. Two palladin isoforms, 140 kDa and 90 kDa, were analysed, with the migration-associated 140-kDa isoform increasing significantly at the time of implantation when compared with the time of fertilisation. Lasp-1 was similarly increased at this time, whilst also being located predominantly apically and laterally in the UECs, suggesting a role in the initial contact between the UECs and the blastocyst. This is the first study to investigate palladin and lasp-1 in the uterine luminal epithelium and suggests an importance for these cytoskeletal proteins in the morphological changes the UECs undergo for pregnancy to occur.

The Cytoskeletal Binding Domain of Band 3 Is Required for Multiprotein Complex Formation and Retention during Erythropoiesis

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 4003-4003
Author(s):  
Timothy J Satchwell ◽  
Bethan R Hawley ◽  
Amanda J Bell ◽  
Maria Leticia Ribeiro ◽  
Ashley M Toye
Keyword(s):  
Plasma Membrane ◽  
Erythrocyte Membrane ◽  
Band 3 ◽  
Multiprotein Complex ◽  
Wild Type ◽  
Membrane Expression ◽  
Protein 4.2 ◽  
Type Band ◽  
Associated Proteins

Abstract The bicarbonate/chloride exchanger protein band 3 is the most abundant protein in the erythrocyte membrane and forms the core of a major multiprotein complex required for vertical association between the plasma membrane and the underlying spectrin cytoskeleton. A wealth of knowledge, derived from a host of varied studies including in vitro binding assays, work on mature erythrocytes and in other cellular systems have identified a number of binding partners including ankyrin, adducin and protein 4.2 amongst others. However, studies of the role that band 3 and the establishment of its connectivity with the cytoskeleton play both in assembly of multiprotein complexes during erythropoiesis and in particular in protein retention during enucleation have been understandably limited by the technical challenges associated with study of this protein within its unique native cellular context. The complete absence of band 3 in human erythrocytes has only been reported once, in a Portuguese patient with severe hereditary spherocytosis and distal renal tubular acidosis resulting from homozygosity for a V488M band 3 mutation (band 3 Coimbra). In this study, we used in vitro culture of erythroblasts derived from this patient as well as shRNA mediated depletion of band 3 to investigate the development of a band 3 deficient erythrocyte membrane and to specifically assess the formation, stability and retention of band 3 dependent protein complexes in the absence of this core protein during erythropoiesis and erythroblast enucleation. We demonstrate that the mutant band 3 Coimbra protein is expressed at very low but detectable levels during erythropoiesis but does not reach the cell surface and is not rescued by interaction with wild type protein. Failure to traffic to the plasma membrane and rapid degradation during erythropoiesis accounts for the absence of band 3 in Coimbra erythrocytes. The absence of plasma membrane expression of band 3 results in secondary deficiencies of a host of band 3 associated membrane proteins that we quantitatively show result predominantly from reduced plasma membrane expression during erythropoiesis compounded by impaired retention in the nascent reticulocyte membrane during erythroblast enucleation. In order to explore the importance of the capacity of band 3 to associate with the cytoskeleton for surface expression of this protein and its associated multiprotein complex binding proteins, immature band 3 Coimbra patient erythroblasts were lentivirally transduced with N terminally GFP-tagged wild type band 3 or band 3 mutants with absent or impaired ability to associate with the cytoskeleton. We demonstrate for the first time the ability to restore expression of band 3 to normal levels in this uniquely compromised patient and to rescue key secondary protein deficiencies arising from the absence of band 3 in reticulocytes. Exogenous expression levels of band 3, monitored by GFP intensity, correlate directly with degree of rescue of a variety of band 3 associated proteins. When expressed in band 3 deficient Coimbra erythroblasts, the band 3 membrane domain, which is unable to associate with the cytoskeleton, exhibits an increased partitioning to the plasma membrane surrounding the extruded nuclei compared to wild type band 3 and fails to rescue reticulocyte membrane retention of band 3 associated proteins. Expression of the kidney isoform of band 3, which is unable to bind ankyrin but retains the binding site for the cytoskeletal accessory protein, protein 4.2 results in partial rescue of the protein 4.2 dependent CD47 only. This demonstrates the importance of band 3 association with the cytoskeleton for efficient retention of band 3 associated proteins during erythroblast enucleation. Interestingly, whilst both exhibit reduced reticulocyte membrane retention relative to wild type, a significant proportion of both band 3 membrane domain and kidney band 3 is retained in the reticulocyte membrane following erythroblast enucleation indicating that cytoskeletal attachment of band 3 is not the sole determinant of partitioning during this complex process. This study advances our understanding of the mechanisms by which the properties of band 3 influence the sculpting and composition of the erythrocyte membrane and highlights the role of this protein as a core for assembly and stabilisation of key membrane proteins in both the early and late stages of terminal erythroid differentiation. Disclosures No relevant conflicts of interest to declare.

Spectrin and Ankyrin-Based Pathways: Metazoan Inventions for Integrating Cells Into Tissues

2001 ◽  
Vol 81 (3) ◽  
pp. 1353-1392 ◽  
Author(s):  
Vann Bennett ◽  
Anthony J. Baines
Keyword(s):  
Endoplasmic Reticulum ◽  
Plasma Membrane ◽  
Striated Muscle ◽  
Membrane Skeleton ◽  
Tissue Level ◽  
Yeast Genome ◽  
Mitotic Spindles ◽  
Molecular Physiology ◽  
Mammalian Erythrocyte ◽  
Associated Proteins

The spectrin-based membrane skeleton of the humble mammalian erythrocyte has provided biologists with a set of interacting proteins with diverse roles in organization and survival of cells in metazoan organisms. This review deals with the molecular physiology of spectrin, ankyrin, which links spectrin to the anion exchanger, and two spectrin-associated proteins that promote spectrin interactions with actin: adducin and protein 4.1. The lack of essential functions for these proteins in generic cells grown in culture and the absence of their genes in the yeast genome have, until recently, limited advances in understanding their roles outside of erythrocytes. However, completion of the genomes of simple metazoans and application of homologous recombination in mice now are providing the first glimpses of the full scope of physiological roles for spectrin, ankyrin, and their associated proteins. These functions now include targeting of ion channels and cell adhesion molecules to specialized compartments within the plasma membrane and endoplasmic reticulum of striated muscle and the nervous system, mechanical stabilization at the tissue level based on transcellular protein assemblies, participation in epithelial morphogenesis, and orientation of mitotic spindles in asymmetric cell divisions. These studies, in addition to stretching the erythrocyte paradigm beyond recognition, also are revealing novel cellular pathways essential for metazoan life. Examples are ankyrin-dependent targeting of proteins to excitable membrane domains in the plasma membrane and the Ca2+homeostasis compartment of the endoplasmic reticulum. Exciting questions for the future relate to the molecular basis for these pathways and their roles in a clinical context, either as the basis for disease or more positively as therapeutic targets.

scholarly journals The actin cytoskeleton and plasma membrane connection: PtdIns(4,5)P(2) influences cytoskeletal protein activity at the plasma membrane

2000 ◽  
Vol 113 (21) ◽  
pp. 3685-3695 ◽  
Author(s):  
A.S. Sechi ◽  
J. Wehland
Keyword(s):  
Plasma Membrane ◽  
Actin Cytoskeleton ◽  
Adhesion Molecules ◽  
Focal Adhesion ◽  
Small Gtpases ◽  
Cytoskeletal Protein ◽  
Protein Activity ◽  
Associated Proteins ◽  
Tight Connection

The co-ordination of rearrangements of the actin cytoskeleton depends on its tight connection to the plasma membrane. Phosphatidylinositol 4,5-bisphosphate is thought to transmit signals originating at the plasma membrane to the underlying actin cytoskeleton. This lipid binds to, and influences the activity of, several actin-associated proteins in vitro that regulate the architecture of the actin cytoskeleton. Signalling intermediates in this process include focal adhesion molecules such as vinculin and members of two families of proteins, ERM and WASP. These proteins interact with phosphatidylinositol 4,5-bisphosphate and appear to be regulated by interplay between small GTPases and phosphatidylinositol 4,5-bisphosphate metabolism, and thus link the plasma membrane with cytoskeletal remodelling.

Biotinylation and Purification of Plasma Membrane-associated Proteins from Rodent Cultured Neurons

BIO-PROTOCOL ◽  
2016 ◽  
Vol 6 (10) ◽  
Author(s):  
Margarida Caldeira ◽  
Joana Ferreira ◽  
Ana Carvalho ◽  
Carlos Duarte
Keyword(s):  
Plasma Membrane ◽  
Cultured Neurons ◽  
Associated Proteins

scholarly journals The polymerization of actin: II. how nonfilamentous actin becomes nonrandomly distributed in sperm: evidence for the association of this actin with membranes

1976 ◽  
Vol 69 (1) ◽  
pp. 51-72 ◽  
Author(s):  
LG Tilney
Keyword(s):  
Plasma Membrane ◽  
Nuclear Envelope ◽  
Thin Section ◽  
Actin Filaments ◽  
Early Stage ◽  
Mature Sperm ◽  
Vacuole Membrane ◽  
Other Substances ◽  
Associated Proteins ◽  
Basal Half

At an early stage in spermiogenesis the acrosomal vacuole and other organelles including ribosomes are located at the basal end of the cell. From here actin must be transported to its future location at the anterior end of the cell. At no stage in the accumulation of actin in the periacrosomal region is the actin sequestered in a membrane-bounded compartment such as a vacuole or vesicle. Since filaments are not present in the periacrosomal region during the accumulation of the actin even though the fixation of these cells is sufficiently good to distinguish actin filaments in thin section, the actin must accumulate in the nonfilamentous state. The membranes in the periacrosomal region, specifically a portion of the nuclear envelope and the basal half of the acrosomal vacuole membrane, become specialized morphologically in advance of the accumulation of actin in this region. My working hypothesis is that the actin in combination with other substances binds to these specialized membranes and to itself and thus can accumulate in the periacrosmoal region by being trapped on these specialized membranes. Diffusion would then be sufficient to move these substances to this region. In support of this hypothesis are experiments in which I treated mature sperm with detergents, glycols, and hypotonic media, which solubilize or lift away the plasma membrane. The actin and its associated proteins remain attached to these specialized membranes. Thus actin can be nonrandomly distributed in cells in a nonfilamentous state presumably by its association with specialized membranes.

scholarly journals Immunomodulatory Effects of Pneumococcal Extracellular Vesicles on Cellular and Humoral Host Defenses

mBio ◽  
2018 ◽  
Vol 9 (2) ◽  
Author(s):  
Mario Codemo ◽  
Sandra Muschiol ◽  
Federico Iovino ◽  
Priyanka Nannapaneni ◽  
Laura Plant ◽  
...  
Keyword(s):  
Dendritic Cells ◽  
Plasma Membrane ◽  
Streptococcus Pneumoniae ◽  
Extracellular Vesicles ◽  
Factor H ◽  
Host Cells ◽  
Immunomodulatory Effects ◽  
Content Type ◽  
Associated Proteins ◽  
Tract Infections

ABSTRACTGram-positive bacteria, including the major respiratory pathogenStreptococcus pneumoniae, were recently shown to produce extracellular vesicles (EVs) that likely originate from the plasma membrane and are released into the extracellular environment. EVs may function as cargo for many bacterial proteins, however, their involvement in cellular processes and their interactions with the innate immune system are poorly understood. Here, EVs from pneumococci were characterized and their immunomodulatory effects investigated. Pneumococcal EVs were protruding from the bacterial surface and released into the medium as 25 to 250 nm lipid stained vesicles containing a large number of cytosolic, membrane, and surface-associated proteins. The cytosolic pore-forming toxin pneumolysin was significantly enriched in EVs compared to a total bacterial lysate but was not required for EV formation. Pneumococcal EVs were internalized into A549 lung epithelial cells and human monocyte-derived dendritic cells and induced proinflammatory cytokine responses irrespective of pneumolysin content. EVs from encapsulated pneumococci were recognized by serum proteins, resulting in C3b deposition and formation of C5b-9 membrane attack complexes as well as factor H recruitment, depending on the presence of the choline binding protein PspC. Addition of EVs to human serum decreased opsonophagocytic killing of encapsulated pneumococci. Our data suggest that EVs may act in an immunomodulatory manner by allowing delivery of vesicle-associated proteins and other macromolecules into host cells. In addition, EVs expose targets for complement factors in serum, promoting pneumococcal evasion of humoral host defense.IMPORTANCEStreptococcus pneumoniaeis a major contributor to morbidity and mortality worldwide, being the major cause of milder respiratory tract infections such as otitis and sinusitis and of severe infections such as community-acquired pneumonia, with or without septicemia, and meningitis. More knowledge is needed on how pneumococci interact with the host, deliver virulence factors, and activate immune defenses. Here we show that pneumococci form extracellular vesicles that emanate from the plasma membrane and contain virulence properties, including enrichment of pneumolysin. We found that pneumococcal vesicles can be internalized into epithelial and dendritic cells and bind complement proteins, thereby promoting pneumococcal evasion of complement-mediated opsonophagocytosis. They also induce pneumolysin-independent proinflammatory responses. We suggest that these vesicles can function as a mechanism for delivery of pneumococcal proteins and other immunomodulatory components into host cells and help pneumococci to avoid complement deposition and phagocytosis-mediated killing, thereby possibly contributing to the symptoms found in pneumococcal infections.

scholarly journals Disorders of the erythrocyte membrane

2015 ◽  
Vol 9 (4) ◽  
pp. 323
Author(s):  
Sophia Delicou ◽  
Aikaterini Xydaki ◽  
Chryssanthi Kontaxi ◽  
Konstantinos Maragkos
Keyword(s):  
Surface Area ◽  
Erythrocyte Membrane ◽  
Structural Integrity ◽  
Mechanical Stability ◽  
Hereditary Spherocytosis ◽  
Membrane Surface ◽  
Membrane Skeleton ◽  
Inherited Disorders ◽  
Hereditary Elliptocytosis ◽  
Area Loss

Hemolytic anemia due to abnormalities of the erythrocyte membrane comprises an important group of inherited disorders. These include hereditary spherocytosis, hereditary elliptocytosis, hereditary pyropoikilocytosis, and the hereditary stomatocytosis syndromes. The erythrocyte membrane skeleton composed of spectrin, actin, and several other proteins is essential for the maintenance of the erythrocyte shape, reversible deformability, and membrane structural integrity in addition to controlling the lateral mobility of integral membrane proteins. These disorders are characterized by clinical and laboratory heterogeneity and, as evidenced by recent molecular studies, by genetic heterogeneity. Defects in various proteins involved in linking the lipid bilayer to membrane skeleton result in loss in membrane cohesion leading to surface area loss and hereditary spherocytosis while defects in proteins involved in lateral interactions of the spectrin-based skeleton lead to decreased mechanical stability, membrane fragmentation and hereditary elliptocytosis. The disease severity is primarily dependent on the extent of membrane surface area loss. Treatment with splenectomy is curative in most patients.

scholarly journals Mapping of a spectrin-binding domain of human erythrocyte membrane protein 4.2

2002 ◽  
Vol 364 (3) ◽  
pp. 841-847 ◽  
Author(s):  
Debabrata MANDAL ◽  
Prasun K. MOITRA ◽  
Joyoti BASU
Keyword(s):  
Erythrocyte Membrane ◽  
Synthetic Peptide ◽  
Membrane Skeleton ◽  
Band 3 Protein ◽  
Fusion Peptides ◽  
Human Erythrocyte Membrane ◽  
Glutathione S Transferase ◽  
Protein 4.2 ◽  
N Terminus ◽  
Direct Binding

Protein 4.2 is a major component of the red blood cell membrane skeleton. Deficiency of protein 4.2 is linked with a variety of hereditary haemolytic anaemias. However, the interactions of protein 4.2 with other proteins of the erythrocyte membrane remain poorly understood. The major membrane-binding site for protein 4.2 resides on the cytoplasmic domain of band 3. Protein 4.2 interacts directly with spectrin in solution, suggesting that it stabilizes interactions between the membrane skeleton and the erythrocyte membrane. A 30kDa polypeptide, with its N-terminus corresponding to amino acid residue 269, derived by partial proteolysis of protein 4.2, was found to interact with biotinylated spectrin in gel renaturation assays. A series of overlapping glutathione S-transferase fusion peptides were constructed, and an α-helical domain encompassing residues 470–492 was found to be instrumental in mediating protein 4.2—spectrin interactions. Direct binding of a synthetic peptide, with the sequence corresponding to residues 470–492, to spectrin and the ability of the peptide to inhibit spectrin binding of protein 4.2 confirmed that these residues are crucial in mediating protein 4.2—spectrin interactions.

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