Formation of diffusion barrier in the plasma membrane of the initial segments: study on lipid movements at a single-molecular level

2000 ◽  
Vol 38 ◽  
pp. S50
Author(s):  
C Nakada
Keyword(s):  
Plasma Membrane ◽  
Diffusion Barrier ◽  
Molecular Level

scholarly journals CD133 Expression in the Nucleus Is Associated with Endometrial Carcinoma Staging and Tumor Angioinvasion

2021 ◽  
Vol 10 (10) ◽  
pp. 2144
Author(s):  
Milosz Pietrus ◽  
Kazimierz Pitynski ◽  
Marcin Waligora ◽  
Katarzyna Milian-Ciesielska ◽  
Monika Bialon ◽  
...  
Keyword(s):  
Endometrial Cancer ◽  
Plasma Membrane ◽  
Tumor Progression ◽  
Endometrial Carcinoma ◽  
Molecular Level ◽  
Risk Group ◽  
High Risk Group ◽  
Cd133 Expression ◽  
Transmembrane Glycoprotein ◽  
The Impact

Background: (1) Endometrial cancer is one of the most common cancers affecting women, with a growing incidence. To better understand the different behaviors associated with endometrial cancer, it is necessary to understand the changes that occur at a molecular level. CD133 is one of the factors that regulate tumor progression, which is primarily known as the transmembrane glycoprotein associated with tumor progression or cancer stem cells. The aim of our study was to assess the impact of subcellular CD133 expression on the clinical course of endometrial cancer. (2) Methods: CD133 expression in the plasma membrane, nucleus, and cytoplasm was assessed by immunohistochemical staining in a group of 64 patients with endometrial cancer representing FIGO I-IV stages, grades 1–3 and accounting for tumor angioinvasion. (3) Results: Nuclear localization of CD133 expression was increased in FIGO IB-IV stages compared to FIGO IA. Furthermore, CD133 expression in the nucleus and plasma membrane is positively and negatively associated with a higher grade of endometrial cancer and angioinvasion, respectively. (4) Conclusions: Our findings suggest that positive nuclear CD133 expression in the tumor may be related to a less favorable prognosis of endometrial carcinoma patients and has emerged as a useful biomarker of a high-risk group.

scholarly journals Developmental formation of a diffusion barrier in the plasma membrane of the axonal initial segment : single lipid molecule approach

2000 ◽  
Vol 40 (supplement) ◽  
pp. S212
Author(s):  
C. Nakada ◽  
M. Nozaki ◽  
H. Yamashita ◽  
K. Yamaguchi ◽  
Ken Ritchie ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Diffusion Barrier ◽  
Initial Segment ◽  
Lipid Molecule ◽  
Axonal Initial Segment

scholarly journals Drosophila ßHeavy-Spectrin is required in polarized ensheathing glia that form a diffusion-barrier around the neuropil

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Nicole Pogodalla ◽  
Holger Kranenburg ◽  
Simone Rey ◽  
Silke Rodrigues ◽  
Albert Cardona ◽  
...  
Keyword(s):  
Nervous System ◽  
Plasma Membrane ◽  
Diffusion Barrier ◽  
Neuronal Cell ◽  
Apical Plasma Membrane ◽  
Neuronal Cell Bodies ◽  
The Central Nervous System ◽  
Basolateral Plasma Membrane ◽  
Nervous System Function ◽  
Spectrin Cytoskeleton

AbstractIn the central nervous system (CNS), functional tasks are often allocated to distinct compartments. This is also evident in the Drosophila CNS where synapses and dendrites are clustered in distinct neuropil regions. The neuropil is separated from neuronal cell bodies by ensheathing glia, which as we show using dye injection experiments, contribute to the formation of an internal diffusion barrier. We find that ensheathing glia are polarized with a basolateral plasma membrane rich in phosphatidylinositol-(3,4,5)-triphosphate (PIP3) and the Na+/K+-ATPase Nervana2 (Nrv2) that abuts an extracellular matrix formed at neuropil-cortex interface. The apical plasma membrane is facing the neuropil and is rich in phosphatidylinositol-(4,5)-bisphosphate (PIP2) that is supported by a sub-membranous ßHeavy-Spectrin cytoskeleton. ßHeavy-spectrin mutant larvae affect ensheathing glial cell polarity with delocalized PIP2 and Nrv2 and exhibit an abnormal locomotion which is similarly shown by ensheathing glia ablated larvae. Thus, polarized glia compartmentalizes the brain and is essential for proper nervous system function.

scholarly journals Breaching the diffusion barrier that compartmentalizes the transmembrane glycoprotein CE9 to the posterior-tail plasma membrane domain of the rat spermatozoon.

1993 ◽  
Vol 120 (3) ◽  
pp. 687-694 ◽  
Author(s):  
C L Nehme ◽  
M M Cesario ◽  
D G Myles ◽  
D E Koppel ◽  
J R Bartles
Keyword(s):  
Plasma Membrane ◽  
T Cell Activation ◽  
Diffusion Barrier ◽  
Transmembrane Protein ◽  
Single Gene ◽  
Immunoglobulin Superfamily ◽  
Tail Domain ◽  
Membrane Domain ◽  
Plasma Membrane Domain ◽  
Testicular Spermatozoon

CE9 is a posterior-tail domain-specific integral plasma membrane glycoprotein of the rat testicular spermatozoon. During epididymal maturation, CE9 undergoes endoproteolytic processing and then redistributes into the anterior-tail plasma membrane domain of the spermatozoon (Petruszak, J. A. M., C. L. Nehme, and J. R. Bartles. 1991. J. Cell. Biol. 114:917-927). We have determined the sequence of CE9 and found it to be a Type Ia transmembrane protein identical to the MRC OX-47 T-cell activation antigen, a member of the immunoglobulin superfamily predicted to have two immunoglobulin-related loops and three asparagine-linked glycans disposed extracellularly. Although encoded by a single gene and mRNA in the rat, the majority of spermatozoal CE9 is of smaller apparent molecular mass than its hepatocytic counterpart due to the under-utilization of sites for asparagine-linked glycosylation. By fluorescence recovery after photobleaching, CE9 was determined to be mobile within the posterior-tail plasma membrane domain of the living rat testicular spermatozoon, thus implying the existence of a regional barrier to lateral diffusion that is presumed to operate at the level of the annulus. Through the development of an in vitro system, the modification of this diffusion barrier to allow for the subsequent redistribution of CE9 into the anterior-tail domain was found to be a time-, temperature-, and energy-dependent process.

scholarly journals Development of a diffusion barrier that compartmentalizes the neuron's plasma membrane into axonal versus somatodendritic zones.

2000 ◽  
Vol 40 (supplement) ◽  
pp. S12
Author(s):  
C. Nakada ◽  
M. Nozaki ◽  
H. Yamashita ◽  
K. Yamaguchi ◽  
Ken Ritchie ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Diffusion Barrier

scholarly journals Role of mitotic diffusion barriers in regulating the asymmetric division of activated CD8 T cells

2021 ◽  
Author(s):  
Hulya Emurla ◽  
Yves Barral ◽  
Annette Oxenius
Keyword(s):  
T Cells ◽  
Plasma Membrane ◽  
Cd8 T Cells ◽  
Diffusion Barrier ◽  
Lateral Diffusion ◽  
Memory Cells ◽  
Effector Cells ◽  
Membrane Asymmetry

SummaryUpon their activation, naïve CD8 T cells divide and differentiate into short-lived effector cells, relevant for exerting immune control, and long-lived memory cells, relevant for long-term immunity. The proportion of memory cells generated depends highly on the context of activation and whether the activated cell divides symmetrically or asymmetrically. However, how T cells control the extent of their asymmetry during their first division in response to contextual signals is not known. Using fluorescence loss in photo-bleaching (FLIP) experiments, we show that the metabolic and plasma membrane asymmetry of mitotic T cells depend on the regulated assembly of a lateral diffusion barrier in their endoplasmic reticulum (ER-) membrane. In asymmetrically dividing T cells, the degrees of asymmetry correlated tightly to barrier strength, whereas symmetrically dividing T cells did not establish such a barrier. Direct positive or negative interference with barrier assembly enhanced or abrogated metabolic and plasma membrane asymmetry, respectively, indicating that barrier strength is a direct and decisive determinant of mitotic asymmetry. Thus, together our data identify diffusion barrier-mediated compartmentalization as a mechanism for how asymmetric T cell regulate their long-term response as a function of the activatory context.

Molecular structure and regulation of vertebrate Na+/H+ exchangers.

1994 ◽  
Vol 196 (1) ◽  
pp. 337-345 ◽  
Author(s):  
L Bianchini ◽  
J Pousségur
Keyword(s):  
Molecular Structure ◽  
Plasma Membrane ◽  
Structure Function ◽  
Cellular Localization ◽  
Molecular Level ◽  
Cellular Functions ◽  
New Gene ◽  
Regulation Mechanisms ◽  
Function Relationship ◽  
Transmembrane Transporters

Na+/H+ exchangers (NHE), also called antiporters, are vital transmembrane transporters involved in multiple cellular functions including the regulation of intracellular pH, the control of cell volume and transepithelial ion transport. These transporters are highly regulated by a remarkably wide variety of stimuli which can modulate their expression level and activity. Five isoforms of Na+/H+ exchangers have been cloned and characterized to date; they define a new gene family of vertebrate transporters. These isoforms share the same overall structure but exhibit differences with respect to amiloride-sensitivity, cellular localization, kinetic variables, regulation by various stimuli and plasma membrane targeting in polarized epithelial cells. Biochemical techniques and molecular genetics tools provide the means of analyzing these transporters at the molecular level. The purpose of this manuscript is to give an overview of the main features of the Na+/H+ exchangers with emphasis on recent advances in comprehension of the structure-function relationship and regulation mechanisms of the ubiquitous isoform: NHE-1.

scholarly journals Rapid Auxin-Mediated Cell Expansion

2020 ◽  
Vol 71 (1) ◽  
pp. 379-402 ◽  
Author(s):  
Minmin Du ◽  
Edgar P. Spalding ◽  
William M. Gray
Keyword(s):  
Plasma Membrane ◽  
Cell Expansion ◽  
Plant Hormone ◽  
Molecular Level ◽  
Good News ◽  
Growth Theory ◽  
Acid Growth ◽  
Promotive Effect ◽  
Acid Growth Theory ◽  
Regulate Protein

The promotive effect of auxin on shoot cell expansion provided the bioassay used to isolate this central plant hormone nearly a century ago. While the mechanisms underlying auxin perception and signaling to regulate transcription have largely been elucidated, how auxin controls cell expansion is only now attaining molecular-level definition. The good news is that the decades-old acid growth theory invoking plasma membrane H+-ATPase activation is still useful. The better news is that a mechanistic framework has emerged, wherein Small Auxin Up RNA (SAUR) proteins regulate protein phosphatases to control H+-ATPase activity. In this review, we focus on rapid auxin effects, their relationship to H+-ATPase activation and other transporters, and dependence on TIR1/AFB signaling. We also discuss how some observations, such as near-instantaneous effects on ion transport and root growth, do not fit into a single, comprehensive explanation of how auxin controls cell expansion, and where more research is warranted.

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