scholarly journals An engineered membrane-bound guanylyl cyclase with light-switchable activity

BMC Biology ◽  
2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Yuehui Tian ◽  
Georg Nagel ◽  
Shiqiang Gao
Keyword(s):  
Guanylyl Cyclase ◽  
Green Light ◽  
Chemical Properties ◽  
Light Sensitivity ◽  
Cgmp Level ◽  
Volvox Carteri ◽  
Non Invasive ◽  
Cgmp Signaling ◽  
Membrane Bound ◽  
Light Flashes

Abstract Background Microbial rhodopsins vary in their chemical properties, from light sensitive ion transport to different enzymatic activities. Recently, a novel family of two-component Cyclase (rhod)opsins (2c-Cyclop) from the green algae Chlamydomonas reinhardtii and Volvox carteri was characterized, revealing a light-inhibited guanylyl cyclase (GC) activity. More genes similar to 2c-Cyclop exist in algal genomes, but their molecular and physiological functions remained uncharacterized. Results Chlamyopsin-5 (Cop5) from C. reinhardtii is related to Cr2c-Cyclop1 (Cop6) and can be expressed in Xenopus laevis oocytes, but shows no GC activity. Here, we exchanged parts of Cop5 with the corresponding ones of Cr2c-Cyclop1. When exchanging the opsin part of Cr2c-Cyclop1 with that of Cop5, we obtained a bi-stable guanylyl cyclase (switch-Cyclop1) whose activity can be switched by short light flashes. The GC activity of switch-Cyclop1 is increased for hours by a short 380 nm illumination and switched off (20-fold decreased) by blue or green light. switch-Cyclop1 is very light-sensitive and can half-maximally be activated by ~ 150 photons/nm2 of 380 nm (~ 73 J/m2) or inhibited by ~ 40 photons/nm2 of 473 nm (~ 18 J/m2). Conclusions This engineered guanylyl cyclase is the first light-switchable enzyme for cGMP level regulation. Light-regulated cGMP production with high light-sensitivity is a promising technique for the non-invasive investigation of the effects of cGMP signaling in many different tissues.

scholarly journals The “Vesicular Intelligence” Strategy of Blood Cancers

Genes ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 416
Author(s):  
Dorian Forte ◽  
Martina Barone ◽  
Francesca Palandri ◽  
Lucia Catani
Keyword(s):  
Clonal Evolution ◽  
Biological Properties ◽  
Hemopoietic Stem Cell ◽  
Target Cells ◽  
Cancer Cell Growth ◽  
Cell Compartment ◽  
Blood Cancer ◽  
Non Invasive ◽  
Membrane Bound ◽  
Immune Potential

Blood cancers are a heterogeneous group of disorders including leukemia, multiple myeloma, and lymphoma. They may derive from the clonal evolution of the hemopoietic stem cell compartment or from the transformation of progenitors with immune potential. Extracellular vesicles (EVs) are membrane-bound nanovesicles which are released by cells into body fluids with a role in intercellular communication in physiology and pathology, including cancer. EV cargos are enriched in nucleic acids, proteins, and lipids, and these molecules can be delivered to target cells to influence their biological properties and modify surrounding or distant targets. In this review, we will describe the “smart strategy” on how blood cancer-derived EVs modulate tumor cell development and maintenance. Moreover, we will also depict the function of microenvironment-derived EVs in blood cancers and discuss how the interplay between tumor and microenvironment affects blood cancer cell growth and spreading, immune response, angiogenesis, thrombogenicity, and drug resistance. The potential of EVs as non-invasive biomarkers will be also discussed. Lastly, we discuss the clinical application viewpoint of EVs in blood cancers. Overall, blood cancers apply a ‘vesicular intelligence’ strategy to spread signals over their microenvironment, promoting the development and/or maintenance of the malignant clone.

scholarly journals The effects of anions on fumarate reductase isolated from the cytoplasmic membrane of Escherichia coli

1981 ◽  
Vol 199 (3) ◽  
pp. 473-477 ◽  
Author(s):  
J J Robinson ◽  
J H Weiner
Keyword(s):  
Escherichia Coli ◽  
Cytoplasmic Membrane ◽  
Chemical Properties ◽  
Fumarate Reductase ◽  
Maximal Velocity ◽  
Nitrobenzoic Acid ◽  
Thiol Reagent ◽  
Membrane Bound ◽  
Physical And Chemical ◽  
And Chemical Properties

A broad range of anions was shown to stimulate the maximal velocity of purified fumarate reductase isolated from the cytoplasmic membrane of Escherichia coli, while leaving the Km for fumarate unaffected. Reducing agents potentiate the effects of anions on the activity, but have no effect by themselves. Thermal stability, conformation as monitored by circular dichroism and susceptibility to the thiol reagent 5,5′-dithiobis-(2-nitrobenzoic acid) are also altered by anions. The apparent Km for succinate in the reverse reaction (succinate dehydrogenase activity) varies as a function of anion concentration, but the maximal velocity is not affected. The membrane-bound activity is not stimulated by anions and its properties closely resemble those of the purified enzyme in the presence of anions. Thus it appears that anions alter the physical and chemical properties of fumarate reductase, so that it more closely resembles the membrane-bound form.

Involvement of guanylyl cyclase and cGMP in the regulation of Mrp2-mediated transport in the proximal tubule

2004 ◽  
Vol 287 (1) ◽  
pp. F33-F38 ◽  
Author(s):  
Sylvia Notenboom ◽  
David S. Miller ◽  
P. Smits ◽  
Frans G. M. Russel ◽  
Rosalinde Masereeuw
Keyword(s):  
Guanylyl Cyclase ◽  
Organic Anion ◽  
No Donor ◽  
Quantitative Image ◽  
Cgmp Signaling ◽  
Cgmp Analog ◽  
A Cell ◽  
Protein Isoform ◽  
Nos Inhibitor ◽  
Oxide Synthase

In killifish renal proximal tubules, endothelin-1 (ET-1), acting through a basolateral ETB receptor, nitric oxide synthase (NOS), and PKC, decreases cell-to-lumen organic anion transport mediated by the multidrug resistance protein isoform 2 (Mrp2). In the present study, we examined the roles of guanylyl cyclase and cGMP in ET signaling to Mrp2. Using confocal microscopy and quantitative image analysis to measure Mrp2-mediated transport of the fluorescent drug fluorescein methotrexate (FL-MTX), we found that oxadiazole quinoxalin (ODQ), an inhibitor of NO-sensitive guanylyl cyclase, blocked ET-1 signaling. ODQ was also effective when signaling was initiated by nephrotoxicants (gentamicin, amikacin, diatrizoate, HgCl2, and CdCl2), which appear to stimulate ET release from the tubules themselves. ODQ blocked the effects of the NO donor sodium nitroprusside but not of the phorbol ester that activates PKC. Exposing tubules to 8-bromo-cGMP (8-BrcGMP), a cell-permeable cGMP analog, decreased luminal FL-MTX accumulation. This effect was abolished by bisindoylmaleimide (BIM), a PKC inhibitor, but not by NG-methyl-l-arginine, a NOS inhibitor. Together, these data indicate that ET regulation of Mrp2 involves activation of guanylyl cyclase and generation of cGMP. Signaling by cGMP follows NO release and precedes PKC activation.

Recent trends in the application of Fourier Transform Infrared (FT-IR) spectroscopy in Heritage Science: from micro- to non-invasive FT-IR

2019 ◽  
Vol 4 (11) ◽  
Author(s):  
F. Rosi ◽  
L. Cartechini ◽  
D. Sali ◽  
C. Miliani
Keyword(s):  
Ir Spectroscopy ◽  
Chemical Properties ◽  
Non Invasive ◽  
High Lateral Resolution ◽  
Heritage Science ◽  
Macro Scale ◽  
Archaeological Materials ◽  
Molecular Specificity ◽  
Ft Ir ◽  
Ft Ir Spectroscopy

Abstract The relevance of FT-IR spectroscopy in heritage science has experienced a constant grow in the last two decades owing to analytical peculiarities that make it an extremely useful tool to answer the questions posed by the study and conservation of art-historical and archaeological materials. High versatility, sensitivity and molecular specificity are, in fact, all requirements that FT-IR spectroscopy fulfils allowing for the investigation of the chemical properties of heritage materials spanning from the micro- to the macro-scale and offering a variety of approaches to minimize sample manipulation and maximize extracted information. Molecular identification and localisation at high lateral resolution of organic and inorganic components in micro-samples was, over recently, the mostly exploited use of FT-IR in heritage science; however, benefiting from technological progress and advances in optical materials and components achieved in the last decade, it now stands out also for non-invasive surface analysis of artworks by fully portable instrumentation.

scholarly journals Pig Intestinal Membrane-Bound Receptor (Guanylyl Cyclase) for Heat-Stable Enterotoxin: cDNA Cloning, Functional Expression, and Characterization

1994 ◽  
Vol 38 (7) ◽  
pp. 535-541 ◽  
Author(s):  
Akihiro Wada ◽  
Toshiya Hirayama ◽  
Saori Kitao ◽  
Jun-ichi Fujisawa ◽  
Yuji Hidaka ◽  
...  
Keyword(s):  
Cdna Cloning ◽  
Guanylyl Cyclase ◽  
Functional Expression ◽  
Heat Stable ◽  
Intestinal Membrane ◽  
Membrane Bound

scholarly journals Urgent cesarean section in a pregnant woman with carbon monoxide poisoning

2014 ◽  
Vol 155 (22) ◽  
pp. 871-875
Author(s):  
Edit Gara ◽  
Éva Gesztes ◽  
Richárd Doroszlai ◽  
Gábor Zacher
Keyword(s):  
Carbon Monoxide ◽  
Pregnant Woman ◽  
Cesarean Section ◽  
Oxygen Therapy ◽  
Carbon Monoxide Poisoning ◽  
Chemical Properties ◽  
Heating Systems ◽  
Carbon Monoxide Intoxication ◽  
Non Invasive ◽  
Physical Chemical

Recognition of carbon monoxide is difficult due to its plain physical-chemical properties. Carbon and gas operating heating systems may cause severe poisoning. Carbon-monoxide intoxication may generate severe hypoxic damage and it may cause death. The authors present the case of severe carbon monoxide poisoning affecting one young child and five adults, including a pregnant woman. Because the availability of hyperbaric oxygen therapy is limited in Hungary, urgent cesarean section was performed to avoid intrauterine hypoxic damage. The authors note that there are no standardized non-invasive methods for measuring fetal carbon-monoxide level and that the level of carbon monoxide accumulation is higher and the clearance is longer in the fetus than in the mother. The pathophysiology of carbon monoxide intoxication and therapeutic options in pregnancy are discussed. Orv. Hetil., 2014, 155(22), 871–875.

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