Carbonic anhydrases IV and IX: subcellular localization and functional role in mouse skeletal muscle

2008 ◽  
Vol 294 (2) ◽  
pp. C402-C412 ◽  
Author(s):  
Renate J. Scheibe ◽  
Karsten Mundhenk ◽  
Tilman Becker ◽  
Janine Hallerdei ◽  
Abdul Waheed ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Plasma Membrane ◽  
Subcellular Localization ◽  
Laser Scanning ◽  
Muscle Fibers ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Mouse Skeletal Muscle ◽  
Ca Ix ◽  
Skeletal Muscle Fibers

The subcellular localization of carbonic anhydrase (CA) IV and CA IX in mouse skeletal muscle fibers has been studied immunohistochemically by confocal laser scanning microscopy. CA IV has been found to be located on the plasma membrane as well as on the sarcoplasmic reticulum (SR) membrane. CA IX is not localized in the plasma membrane but in the region of the t-tubular (TT)/terminal SR membrane. CA IV contributes 20% and CA IX 60% to the total CA activity of SR membrane vesicles isolated from mouse skeletal muscles. Our aim was to examine whether SR CA IV and TT/SR CA IX affect muscle contraction. Isolated fiber bundles of fast-twitch extensor digitorum longus and slow-twitch soleus muscle from mouse were investigated for isometric twitch and tetanic contractions and by a fatigue test. The muscle functions of CA IV knockout (KO) fibers and of CA IX KO fibers do not differ from the function of wild-type (WT) fibers. Muscle function of CA IV/XIV double KO mice unexpectedly shows a decrease in rise and relaxation time and in force of single twitches. In contrast, the CA inhibitor dorzolamide, whether applied to WT or to double KO muscle fibers, leads to a significant increase in rise time and force of twitches. It is concluded that the function of mouse skeletal muscle fibers expressing three membrane-associated CAs, IV, IX, and XIV, is not affected by the lack of one isoform but is possibly affected by the lack of all three CAs, as indicated by the inhibition studies.

scholarly journals Ultrastructural Localization of Histidine-rich Glycoprotein in Skeletal Muscle Fibers: Colocalization With AMP Deaminase

2019 ◽  
Vol 68 (2) ◽  
pp. 139-148
Author(s):  
Letizia Mattii ◽  
Francesco Bianchi ◽  
Alessandra Falleni ◽  
Sabina Frascarelli ◽  
Matilde Masini ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Sarcoplasmic Reticulum ◽  
Laser Scanning ◽  
Muscle Fibers ◽  
Ultrastructural Localization ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Amp Deaminase ◽  
Skeletal Muscle Fibers ◽  
Nuclear Levels

Histidine-rich glycoprotein (HRG) is a plasma protein synthesized by the liver. We have given the first evidence of a tissue localization of HRG demonstrating its presence in skeletal muscle, associated with the zinc enzyme AMP deaminase (AMPD1). Moreover, we have shown that muscle cells do not synthesize HRG, but they can internalize it from plasma. We have recently demonstrated by confocal laser scanning microscopy that in human skeletal muscle, HRG is mainly localized in the myofibrils, preferentially at the I-band of the sarcomere, in the sarcoplasm, and in the nuclei. Using transmission electron microscopy and immunogold analysis, we carried out this study on human and rat normal skeletal muscles with the purpose to deepen the ultrastructural localization of HRG in skeletal muscle fibers. The immunogold analysis evidenced the presence of HRG in the sarcomeres, mainly in the I-band and to a less extent in the A-band, in the heterochromatin of nuclei, and in the sarcoplasmic reticulum. The colocalization of HRG and skeletal muscle AMPD1 was also analyzed. A colabeling of HRG and AMPD1 was evident at sarcomeric, sarcoplasmic reticulum, and nuclear levels. The significance of these interesting and new results is discussed in this article.

scholarly journals Fig mosaic emaravirus p4 protein is involved in cell-to-cell movement

2013 ◽  
Vol 94 (3) ◽  
pp. 682-686 ◽  
Author(s):  
Kazuya Ishikawa ◽  
Kensaku Maejima ◽  
Ken Komatsu ◽  
Osamu Netsu ◽  
Takuya Keima ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Laser Scanning ◽  
Movement Protein ◽  
Rna Virus ◽  
Cell Movement ◽  
Plant Cells ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Series Of Experiments ◽  
Fig Mosaic Virus

Fig mosaic virus (FMV), a member of the newly formed genus Emaravirus, is a segmented negative-strand RNA virus. Each of the six genomic FMV segments contains a single ORF: that of RNA4 encodes the protein p4. FMV-p4 is presumed to be the movement protein (MP) of the virus; however, direct experimental evidence for this is lacking. We assessed the intercellular distribution of FMV-p4 in plant cells by confocal laser scanning microscopy and we found that FMV-p4 was localized to plasmodesmata and to the plasma membrane accompanied by tubule-like structures. A series of experiments designed to examine the movement functions revealed that FMV-p4 has the capacity to complement viral cell-to-cell movement, prompt GFP diffusion between cells, and spread by itself to neighbouring cells. Altogether, our findings demonstrated that FMV-p4 shares several properties with other viral MPs and plays an important role in cell-to-cell movement.

scholarly journals Vacuolar-type H+-ATPase regulates cytoplasmic pH in Toxoplasma gondii tachyzoites

1998 ◽  
Vol 330 (2) ◽  
pp. 853-860 ◽  
Author(s):  
N. J. Silvia MORENO ◽  
Li ZHONG ◽  
Hong-Gang LU ◽  
Wanderley DE SOUZA ◽  
Marlene BENCHIMOL
Keyword(s):  
Plasma Membrane ◽  
Toxoplasma Gondii ◽  
Laser Scanning ◽  
Membrane Surface ◽  
Surface Proteins ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Dependent Manner ◽  
Cytoplasmic Ph ◽  
Bafilomycin A1

Cytoplasmic pH (pHi) regulation was studied in Toxoplasma gondii tachyzoites by using the fluorescent dye 2ʹ,7ʹ-bis-(2-carboxyethyl)-5(6)-carboxyfluorescein. Their mean baseline pHi (7.07±0.06; n = 5) was not significantly affected in the absence of extracellular Na+, K+ or HCO3- but was significantly decreased in a dose-dependent manner by low concentrations of N,Nʹ-dicyclohexylcarbodi-imide (DCCD), N-ethylmaleimide (NEM) or bafilomycin A1. Bafilomycin A1 also inhibited the recovery of tachyzoite pHi after an acid load with sodium propionate. Similar concentrations of DCCD, NEM and bafilomycin A1 produced depolarization of the plasma membrane potential as measured with bis-(1,3-diethylthiobarbituric)trimethineoxonol (bisoxonol), and DCCD prevented the hyperpolarization that accompanies acid extrusion after the addition of propionate, in agreement with the electrogenic nature of this pump. Confocal laser scanning microscopy indicated that, in addition to being located in cytoplasmic vacuoles, the vacuolar (V)-H+-ATPase of T. gondii tachyzoites is also located in the plasma membrane. Surface localization of the V-H+-ATPase was confirmed by experiments using biotinylation of cell surface proteins and immunoprecipitation with antibodies against V-H+-ATPases. Taken together, the results are consistent with the presence of a functional V-H+-ATPase in the plasma membrane of these intracellular parasites and with an important role of this enzyme in the regulation of pHi homoeostasis in these cells.

scholarly journals Immunohistochemical localization in normal tissues of different epitopes in the multidrug transport protein P170: evidence for localization in brain capillaries and crossreactivity of one antibody with a muscle protein.

1989 ◽  
Vol 37 (2) ◽  
pp. 159-164 ◽  
Author(s):  
F Thiebaut ◽  
T Tsuruo ◽  
H Hamada ◽  
M M Gottesman ◽  
I Pastan ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Plasma Membrane ◽  
Cardiac Muscle ◽  
Muscle Fibers ◽  
Transport Protein ◽  
Rat Tissues ◽  
Human Tissues ◽  
Normal Tissues ◽  
Skeletal Muscle Fibers ◽  
Muscle Myosin

Using peroxidase immunohistochemistry, we examined the distribution of P170, a multidrug transport protein, in normal tissues by use of two different monoclonal antibodies (MAb). MAb MRK16 is a MAb that has been shown to react with an epitope in P170 located on the external face of the plasma membrane of multidrug-resistant human cells. MAb C219 has been shown to react with P170 in many mammalian species, and detects an epitope located on the cytoplasmic face of the plasma membrane. Using MRK16, we have previously described the localization of P170 on the bile canalicular face of hepatocytes, the apical surface of proximal tubular cells in kidney, and the surface epithelium in the lower GI tract in normal human tissues. In this work, we report that MRK16 also detects P170 in the capillaries of some human brain samples. A similar pattern was found using MAb C219 in rat tissues. in addition, MAb C219 showed intense localization in selected skeletal muscle fibers and all cardiac muscle fibers in rat and human tissues. ATPase cytochemistry showed that these reactive skeletal muscle fibers were of the type I (slow-twitch) class. Other additional sites of C219 reactivity in rat tissues were found in pancreatic acini, seminal vesicle, and testis. Electrophoretic gel immunoblotting showed two protein bands reactive with MAb C219. In liver, MAb C219 reacted with a approximately 170 KD band. In skeletal and cardiac muscle, MAb C219 reacted with a approximately 200 KD band which migrated in the same position as myosin. This band also reacted with an antibody to skeletal muscle myosin. This result suggests that C219 may crossreact with the heavy chain of muscle myosin in cardiac and skeletal muscle. Because MAb C219 reacts with proteins other than P170, it should be used with caution in studies of multidrug resistance.

Evidence for Na+/Ca2+exchange in intact single skeletal muscle fibers from the mouse

1998 ◽  
Vol 274 (4) ◽  
pp. C940-C946 ◽  
Author(s):  
Christopher D. Balnave ◽  
David G. Allen
Keyword(s):  
Skeletal Muscle ◽  
Sarcoplasmic Reticulum ◽  
Muscle Fibers ◽  
Exchange Mechanism ◽  
Initial Exposure ◽  
Mouse Skeletal Muscle ◽  
Reverse Mode ◽  
Skeletal Muscle Fibers ◽  
Plateau Level ◽  
Sustained Increase

The myoplasmic free Ca2+concentration ([Ca2+]i) was measured in intact single fibers from mouse skeletal muscle with the fluorescent Ca2+ indicator indo 1. Some fibers were perfused in a solution in which the concentration of Na+ was reduced from 145.4 to 0.4 mM (low-Na+solution) in an attempt to activate reverse-mode Na+/Ca2+exchange (Ca2+ entry in exchange for Na+ leaving the cell). Under normal resting conditions, application of low-Na+ solution only increased [Ca2+]iby 5.8 ± 1.8 nM from a mean resting [Ca2+]iof 42 nM. In other fibers, [Ca2+]iwas elevated by stimulating sarcoplasmic reticulum (SR) Ca2+ release with caffeine (10 mM) and by inhibiting SR Ca2+ uptake with 2,5-di( tert-butyl)-1,4-benzohydroquinone (TBQ; 0.5 μM) in an attempt to activate forward-mode Na+/Ca2+exchange (Ca2+ removal from the cell in exchange for Na+ influx). These two agents caused a large increase in [Ca2+]i, which then declined to a plateau level approximately twice the baseline [Ca2+]iover 20 min. If the cell was allowed to recover between exposures to caffeine and TBQ in a solution in which Ca2+ had been removed, the increase in [Ca2+]iduring the second exposure was very low, suggesting that Ca2+ had left the cell during the initial exposure. Application of caffeine and TBQ to a preparation in low-Na+ solution produced a large, sustained increase in [Ca2+]iof ∼1 μM. However, when cells were exposed to caffeine and TBQ in a low-Na+ solution in which Ca2+ had been removed, a sustained increase in [Ca2+]iwas not observed, although [Ca2+]iremained higher and declined slower than in normal Na+ solution. This suggests that forward-mode Na+/Ca2+exchange contributed to the fall of [Ca2+]iin normal Na+ solution, but when extracellular Na+ was low, a prolonged elevation of [Ca2+]icould activate reverse-mode Na+/Ca2+exchange. The results provide evidence that skeletal muscle fibers possess a Na+/Ca2+exchange mechanism that becomes active in its forward mode when [Ca2+]iis increased to levels similar to that obtained during contraction.

scholarly journals Evidence TRPV4 contributes to mechanosensitive ion channels in mouse skeletal muscle fibers

Channels ◽  
2012 ◽  
Vol 6 (4) ◽  
pp. 246-254 ◽  
Author(s):  
Tiffany C. Ho ◽  
Natalie A. Horn ◽  
Tuan Huynh ◽  
Lucy Kelava ◽  
Jeffry B. Lansman
Keyword(s):  
Skeletal Muscle ◽  
Ion Channels ◽  
Muscle Fibers ◽  
Mouse Skeletal Muscle ◽  
Mechanosensitive Ion Channels ◽  
Skeletal Muscle Fibers
Sign in / Sign up

Export Citation Format

Share Document