Clarification of role of ATP in red-cell morphology and function

Nature ◽  
1977 ◽  
Vol 265 (5590) ◽  
pp. 166-168 ◽  
Author(s):  
C. FEO ◽  
N. MOHANDAS
Keyword(s):  
Cell Morphology ◽  
Red Cell ◽  
And Function

An acellular human amnionic membrane model for in vitro culture of type ii pneumocytes: The role of the basement membrane in cell morphology and function

1984 ◽  
Vol 121 (1) ◽  
pp. 215-225 ◽  
Author(s):  
Jamson S. Lwebuga-Mukasa ◽  
Gunilla Thulin ◽  
Joseph A. Madri ◽  
Carolyn Barrett ◽  
Joseph B. Warshaw
Keyword(s):  
Basement Membrane ◽  
In Vitro Culture ◽  
Cell Morphology ◽  
Membrane Model ◽  
Type Ii ◽  
Type Ii Pneumocytes ◽  
And Function

Hereditary spherocytosis in zebrafish riesling illustrates evolution of erythroid beta-spectrin structure, and function in red cell morphogenesis and membrane stability

Development ◽  
2000 ◽  
Vol 127 (23) ◽  
pp. 5123-5132 ◽  
Author(s):  
E.C. Liao ◽  
B.H. Paw ◽  
L.L. Peters ◽  
A. Zapata ◽  
S.J. Pratt ◽  
...  
Keyword(s):  
Cell Morphology ◽  
Membrane Integrity ◽  
Cell Types ◽  
Structure And Function ◽  
Red Cells ◽  
Organelle Transport ◽  
Pleckstrin Homology Domain ◽  
Red Cell ◽  
Human Ortholog ◽  
And Function

Spectrins are key cytoskeleton proteins with roles in membrane integrity, cell morphology, organelle transport and cell polarity of varied cell types during development. Defects in erythroid spectrins in humans result in congenital hemolytic anemias with altered red cell morphology. Although well characterized in mammals and invertebrates, analysis of the structure and function of non-mammalian vertebrate spectrins has been lacking. The zebrafish riesling (ris) suffers from profound anemia, where the developing red cells fail to assume terminally differentiated erythroid morphology. Using comparative genomics, erythroid beta-spectrin (sptb) was identified as the gene mutated in ris. Zebrafish Sptb shares 62.3% overall identity with the human ortholog and phylogenetic comparisons suggest intragenic duplication and divergence during evolution. Unlike the human and murine orthologs, the pleckstrin homology domain of zebrafish Sptb is not removed in red cells by alternative splicing. In addition, apoptosis and abnormal microtubule marginal band aggregation contribute to hemolysis of mutant erythrocytes, which are features not present in mammalian red cells with sptb defects. This study presents the first genetic characterization of a non-mammalian vertebrate sptb and demonstrates novel features of red cell hemolysis in non-mammalian red cells. Further, we propose that the distinct mammalian erythroid morphology may have evolved from specific modifications of Sptb structure and function.

The orientation of sickle hemoglobin fibers within fascicles

1988 ◽  
Vol 46 ◽  
pp. 400-401
Author(s):  
Christopher A. Miller ◽  
Bridget Carragher ◽  
William A. McDade ◽  
Robert Josephs
Keyword(s):  
Sickle Cell ◽  
Sickle Cell Anemia ◽  
Relative Orientation ◽  
Unit Cell ◽  
Red Cell ◽  
High Ph ◽  
Sickle Hemoglobin ◽  
Polar Crystal ◽  
Helical Configuration

Highly ordered bundles of deoxyhemoglobin S (HbS) fibers, termed fascicles, are intermediates in the high pH crystallization pathway of HbS. These fibers consist of 7 Wishner-Love double strands in a helical configuration. Since each double strand has a polarity, the odd number of double strands in the fiber imparts a net polarity to the structure. HbS crystals have a unit cell containing two double strands, one of each polarity, resulting in a net polarity of zero. Therefore a rearrangement of the double strands must occur to form a non-polar crystal from the polar fibers. To determine the role of fascicles as an intermediate in the crystallization pathway it is important to understand the relative orientation of fibers within fascicles. Furthermore, an understanding of fascicle structure may have implications for the design of potential sickling inhibitors, since it is bundles of fibers which cause the red cell distortion responsible for the vaso-occlusive complications characteristic of sickle cell anemia.

Scanning electron microscopic study of collagen fibrillogenesis and extracellular compartmentalization in the chick embryo tendon

1986 ◽  
Vol 44 ◽  
pp. 208-209
Author(s):  
Grace C.H. Yang
Keyword(s):  
Chick Embryo ◽  
Extracellular Space ◽  
Fibroblast Cell ◽  
Collagen Fibrils ◽  
Electron Microscopic ◽  
Voltage Electron ◽  
Scanning Electron Microscopic Study ◽  
Microscopic Studies ◽  
And Function

The size and organization of collagen fibrils in the extracellular matrix is an important determinant of tissue structure and function. The synthesis and deposition of collagen involves multiple steps which begin within the cell and continue in the extracellular space. High-voltage electron microscopic studies of the chick embryo cornea and tendon suggested that the extracellular space is compartmentalized by the fibroblasts for the regulation of collagen fibril, bundle, and tissue specific macroaggregate formation. The purpose of this study is to gather direct evidence regarding the association of the fibroblast cell surface with newly formed collagen fibrils, and to define the role of the fibroblast in the control and the precise positioning of collagen fibrils, bundles, and macroaggregates during chick tendon development.

Role of the Cilia Membrane in Control of Microtubule Sliding

1980 ◽  
Vol 38 ◽  
pp. 612-615
Author(s):  
Edna S. Kaneshiro
Keyword(s):  
Control Mechanism ◽  
Beat Frequency ◽  
Surface Membrane ◽  
Ciliary Membrane ◽  
Ciliary Beating ◽  
Ciliary Reversal ◽  
Voltage Dependent ◽  
Reversal Mechanism ◽  
And Function

It is currently believed that ciliary beating results from microtubule sliding which is restricted in regions to cause bending. Cilia beat can be modified to bring about changes in beat frequency, cessation of beat and reversal in beat direction. In ciliated protozoans these modifications which determine swimming behavior have been shown to be related to intracellular (intraciliary) Ca2+ concentrations. The Ca2+ levels are in turn governed by the surface ciliary membrane which exhibits increased Ca2+ conductance (permeability) in response to depolarization. Mutants with altered behaviors have been isolated. Pawn mutants fail to exhibit reversal of the effective stroke of ciliary beat and therefore cannot swim backward. They lack the increased inward Ca2+ current in response to depolarizing stimuli. Both normal and pawn Paramecium made leaky to Ca2+ by Triton extrac¬tion of the surface membrane exhibit backward swimming only in reactivating solutions containing greater than IO-6 M Ca2+ Thus in pawns the ciliary reversal mechanism itself is left operational and only the control mechanism at the membrane is affected. The topographic location of voltage-dependent Ca2+ channels has been identified as a component of the ciliary mem¬brane since the inward Ca2+ conductance response is eliminated by deciliation and the return of the response occurs during cilia regeneration. Since the ciliary membrane has been impli¬cated in the control of Ca2+ levels in the cilium and therefore is the site of at least one kind of control of microtubule sliding, we have focused our attention on understanding the structure and function of the membrane.

POPDC proteins and cardiac function

2019 ◽  
Vol 47 (5) ◽  
pp. 1393-1404 ◽  
Author(s):  
Thomas Brand
Keyword(s):  
Potential Role ◽  
Striated Muscle ◽  
Short Review ◽  
Effector Proteins ◽  
Muscle Disease ◽  
Disease Genes ◽  
Protein Protein Interaction ◽  
Interaction Partners ◽  
And Function

Abstract The Popeye domain-containing gene family encodes a novel class of cAMP effector proteins in striated muscle tissue. In this short review, we first introduce the protein family and discuss their structure and function with an emphasis on their role in cyclic AMP signalling. Another focus of this review is the recently discovered role of POPDC genes as striated muscle disease genes, which have been associated with cardiac arrhythmia and muscular dystrophy. The pathological phenotypes observed in patients will be compared with phenotypes present in null and knockin mutations in zebrafish and mouse. A number of protein–protein interaction partners have been discovered and the potential role of POPDC proteins to control the subcellular localization and function of these interacting proteins will be discussed. Finally, we outline several areas, where research is urgently needed.

Role of the 807 C/T Polymorphism of the α2 Gene in Platelet GP Ia Collagen Receptor Expression and Function

1999 ◽  
Vol 81 (06) ◽  
pp. 951-956 ◽  
Author(s):  
J. Corral ◽  
R. González-Conejero ◽  
J. Rivera ◽  
F. Ortuño ◽  
P. Aparicio ◽  
...  
Keyword(s):  
Venous Thrombosis ◽  
Cell Types ◽  
Receptor Expression ◽  
Case Control Studies ◽  
Platelet Surface ◽  
Vitro Analysis ◽  
And Function ◽  
In Vitro Analysis

SummaryThe variability of the platelet GP Ia/IIa density has been associated with the 807 C/T polymorphism (Phe 224) of the GP Ia gene in American Caucasian population. We have investigated the genotype and allelic frequencies of this polymorphism in Spanish Caucasians. The T allele was found in 35% of the 284 blood donors analyzed. We confirmed in 159 healthy subjects a significant association between the 807 C/T polymorphism and the platelet GP Ia density. The T allele correlated with high number of GP Ia molecules on platelet surface. In addition, we observed a similar association of this polymorphism with the expression of this protein in other blood cell types. The platelet responsiveness to collagen was determined by “in vitro” analysis of the platelet activation and aggregation response. We found no significant differences in these functional platelet parameters according to the 807 C/T genotype. Finally, results from 3 case/control studies involving 302 consecutive patients (101 with coronary heart disease, 104 with cerebrovascular disease and 97 with deep venous thrombosis) determined that the 807 C/T polymorphism of the GP Ia gene does not represent a risk factor for arterial or venous thrombosis.

Von Willebrand disease and Weibel-Palade bodies

2010 ◽  
Vol 30 (03) ◽  
pp. 150-155 ◽  
Author(s):  
J. W. Wang ◽  
J. Eikenboom
Keyword(s):  
Platelet Adhesion ◽  
Coagulation Factor ◽  
Von Willebrand Disease ◽  
Inflammatory Factors ◽  
Limited Data ◽  
Storage Organelle ◽  
And Function ◽  
Von Willebrand ◽  
Willebrand Factor

SummaryVon Willebrand factor (VWF) is a pivotal haemostatic protein mediating platelet adhesion to injured endothelium and carrying coagulation factor VIII (FVIII) in the circulation to protect it from premature clearance. Apart from the roles in haemostasis, VWF drives the formation of the endothelial cell specific Weibel-Palade bodies (WPBs), which serve as a regulated storage of VWF and other thrombotic and inflammatory factors. Defects in VWF could lead to the bleeding disorder von Willebrand disease (VWD).Extensive studies have shown that several mutations identified in VWD patients cause an intracellular retention of VWF. However, the effects of such mutations on the formation and function of its storage organelle are largely unknown. This review gives an overview on the role of VWF in WPB biogenesis and summarizes the limited data on the WPBs formed by VWD-causing mutant VWF.

Identifikasi Peran dan Strategi Pelabuhan Bebas Sabang

2020 ◽  
Vol 4 (3) ◽  
pp. 167-178
Author(s):  
Zurayna Sari
Keyword(s):  
Economic Development ◽  
Descriptive Analysis ◽  
Regional Growth ◽  
Maintenance Strategy ◽  
Regional Economic ◽  
Growth Center ◽  
Free Port ◽  
And Function ◽  
Role And Function

ABSTRAKPelabuhan berperan sebagai fasilitas penunjang pusat pertumbuhan regional dalam proses pembangunan ekonomi wilayah. Pelabuhan Bebas Sabang diarahkan sebagai pusat pertumbuhan ekonomi regional dan diharapkan dapat meningkatkan perekonomian Kawasan Sabang. Permasalahan yang dihadapi Pelabuhan Bebas Sabang adalah belum optimalnya peran dan fungsi Pelabuhan Bebas Sabang dalam menunjang perekonomian wilayah. Penelitian ini bertujuan untuk mengetahui peran Pelabuhan Bebas Sabang dalam mendorong perkembangan perekonomian Kawasan Sabang. Lingkup materi yang dibahas mencakup peran-peran Pelabuhan Bebas Sabang, menentukan potensi dan masalah serta upaya-upaya peningkatan peran Pelabuhan Bebas Sabang. Metode analisis yang dilakukan adalah analisis deskriptif dengan pendekatan analisis data kualitatif dan kuantitatif. Alat analisis yang digunakan adalah analisis SWOT IFAS-EFAS. Hasil analisis menunjukkan dalam kurun waktu 4 (empat) tahun terakhir dari tahun 2010-2013, Pelabuhan Bebas Sabang belum optimal dalam menjalankan perannya, sehingga membutuhkan strategi pengembangan dengan pendekatan Agressive Maintenance Strategy (strategi perbaikan agresif), yaitu strategi konsolidasi internal dengan memperbaiki faktor-faktor kelemahan untuk memaksimalkan pemanfaatan peluang.Kata kunci: Pengelolaan, SWOT IFAS-EFAS, WilayahABSTRACTPort was supporting facility of regional growth center in the process of regional economic development. Sabang free port was directed as the center of regional economic growth and expected to raise the economy of sabang. Problems faced by sabang free port was yet optimal role and function in supporting the economy of the region. This study aimed to determine the role of sabang free port in supporting the economic development of sabang. The covered material scope included roles of sabang free port, determining the potentials and problems and efforts of increasing the role of sabang free port. The method of analysis was descriptive analysis with qualitative and quantitative approach. The analytical tool used was the swot ifas-efas analysis. The analysis results showed in the period of 4 (four) years from 2010 until 2013, sabang free port was not optimal in carrying out its role yet, so it requires development strategies with agressive maintenance strategy approach, which is internal consolidation strategy by improving vulnerability factors to maximize the utilization of opportunities.Keywords:, Management, Regional, SWOT IFAS-EFAS

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