scholarly journals Thimet Oligopeptidase—A Classical Enzyme with New Function and New Form

Immuno ◽  
2021 ◽  
Vol 1 (4) ◽  
pp. 332-346
Author(s):  
Yu Liu ◽  
Jeffrey A. Sigman ◽  
Lisa A. Bruce ◽  
Adele J. Wolfson
Keyword(s):  
Immune Responses ◽  
Extracellular Space ◽  
Bioactive Peptides ◽  
Angiotensin I ◽  
Cell Plasma Membrane ◽  
Cell Plasma ◽  
New Findings ◽  
Classical Function ◽  
Peptide Precursors ◽  
Thimet Oligopeptidase

Peptidases generate bioactive peptides that can regulate cell signaling and mediate intercellular communication. While the processing of peptide precursors is initiated intracellularly, some modifications by peptidases may be conducted extracellularly. Thimet oligopeptidase (TOP) is a peptidase that processes neuroendocrine peptides with roles in mood, metabolism, and immune responses, among other functions. TOP also hydrolyzes angiotensin I to angiotensin 1–7, which may be involved in the pathophysiology of COVID-19 infection. Although TOP is primarily cytosolic, it can also be associated with the cell plasma membrane or secreted to the extracellular space. Recent work indicates that membrane-associated TOP can be released with extracellular vesicles (EVs) to the extracellular space. Here we briefly summarize the enzyme’s classical function in extracellular processing of neuroendocrine peptides, as well as its more recently understood role in intracellular processing of various peptides that impact human diseases. Finally, we discuss new findings of EV-associated TOP in the extracellular space.

Stimulation of Tumor-Specific Immunity Using Tumor Cell Plasma Membrane Antigen

Methods ◽  
1997 ◽  
Vol 12 (2) ◽  
pp. 155-164 ◽  
Author(s):  
Matthew F Mescher ◽  
Elena Savelieva
Keyword(s):  
Plasma Membrane ◽  
Tumor Cell ◽  
Cell Plasma Membrane ◽  
Specific Immunity ◽  
Cell Plasma ◽  
Stimulation Of

PROTEIN KINASE ACTIVITY ASSOCIATED WITH THE FAT CELL PLASMA MEMBRANE

1981 ◽  
Vol 9 (2) ◽  
pp. 232P-232P
Author(s):  
G. J. Belsham ◽  
R. W. Brownsey ◽  
R. M. Denton
Keyword(s):  
Plasma Membrane ◽  
Protein Kinase ◽  
Kinase Activity ◽  
Protein Kinase Activity ◽  
Fat Cell ◽  
Cell Plasma Membrane ◽  
Cell Plasma

Gastrointestinal Cell Plasma Membrane Wounding and Resealing In Vivo

1989 ◽  
Vol 96 (5) ◽  
pp. 1238-1248 ◽  
Author(s):  
Paul L. McNeil ◽  
Susumu Ito
Keyword(s):  
Plasma Membrane ◽  
Cell Plasma Membrane ◽  
Cell Plasma

scholarly journals A murine model of Charcot-Marie-Tooth disease 4F reveals a role for the C-terminus of periaxin in the formation and stabilization of Cajal bands

2018 ◽  
Vol 3 ◽  
pp. 20 ◽  
Author(s):  
Diane L. Sherman ◽  
Peter J. Brophy
Keyword(s):  
Plasma Membrane ◽  
Schwann Cell ◽  
Laminin Receptor ◽  
Cell Plasma Membrane ◽  
Charcot Marie Tooth ◽  
Charcot Marie Tooth Disease ◽  
C Terminus ◽  
Cell Plasma ◽  
Inherited Neuropathies ◽  
Tooth Disease

Charcot-Marie-Tooth (CMT) disease comprises up to 80 monogenic inherited neuropathies of the peripheral nervous system (PNS) that collectively result in demyelination and axon degeneration. The majority of CMT disease is primarily either dysmyelinating or demyelinating in which mutations affect the ability of Schwann cells to either assemble or stabilize peripheral nerve myelin. CMT4F is a recessive demyelinating form of the disease caused by mutations in the Periaxin (PRX) gene. Periaxin (Prx) interacts with Dystrophin Related Protein 2 (Drp2) in an adhesion complex with the laminin receptor Dystroglycan (Dag). In mice the Prx/Drp2/Dag complex assembles adhesive domains at the interface between the abaxonal surface of the myelin sheath and the cytoplasmic surface of the Schwann cell plasma membrane. Assembly of these appositions causes the formation of cytoplasmic channels called Cajal bands beneath the surface of the Schwann cell plasma membrane. Loss of either Periaxin or Drp2 disrupts the appositions and causes CMT in both mouse and man. In a mouse model of CMT4F, complete loss of Periaxin first prevents normal Schwann cell elongation resulting in abnormally short internodal distances which can reduce nerve conduction velocity, and subsequently precipitates demyelination. Distinct functional domains responsible for Periaxin homodimerization and interaction with Drp2 to form the Prx/Drp2/Dag complex have been identified at the N-terminus of Periaxin. However, CMT4F can also be caused by a mutation that results in the truncation of Periaxin at the extreme C-terminus with the loss of 391 amino acids. By modelling this in mice, we show that loss of the C-terminus of Periaxin results in a surprising reduction in Drp2. This would be predicted to cause the observed instability of both appositions and myelin, and contribute significantly to the clinical phenotype in CMT4F.

scholarly journals Cell nucleus and membrane recovery after exposure to microwaves

2011 ◽  
Vol 65 (1-2) ◽  
pp. 13-20 ◽  
Author(s):  
Yuriy Shckorbatov ◽  
Vladimir Pasiuga ◽  
Nicolay Kolchigin ◽  
Valentin Grabina ◽  
Dmitry Ivanchenko ◽  
...  
Keyword(s):  
Membrane Permeability ◽  
Cell Nucleus ◽  
Trypan Blue ◽  
Initial Level ◽  
Chromatin Condensation ◽  
Buccal Cells ◽  
Cell Plasma Membrane ◽  
Plasma Membrane Permeability ◽  
Microwave Exposure ◽  
Cell Plasma

Cell nucleus and membrane recovery after exposure to microwaves Cells of human buccal epithelium of six male donors were exposed to microwave radiation (frequency f = 36.64 GHz, power density W = 0.1, 1 and 4 W/m2). Exposure time was 10 seconds. The state of chromatin in cell nucleus was estimated by a number of heterochromatin granules after staining with 2% orcein in 45% acetic acid. Permeability of cell membranes was estimated by percentage of unstained cells after 5 min of staining the cells with vital dyes trypan blue (0.5%) and indigocarmine (5 mM). Cell exposure to microwaves induced chromatin condensation (increase of the number of heterochromatin granules) and increase of membrane permeability to trypan blue and indigocarmine. Isolated human buccal cells demonstrated the ability to recover after microwave exposure. The number of heterochromatin granules decreased to its initial level after 0.5 hour (W = 0.1 W/m2) and 2 hours (W = 1 and 4 W/m2) after cell exposure. Cell plasma membrane permeability recovered later — after 1 hour and 3 hours post exposure, respectively.

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