Salinity induced alterations in photosynthetic and oxidative regulation are ameliorated as a function of salt secretion

Author(s):  
Tabassum Hussain ◽  
Jingsong Li ◽  
Xiaohui Feng ◽  
Hina Asrar ◽  
Bilquees Gul ◽  
...  
2014 ◽  
Vol 2014 ◽  
pp. 1-14 ◽  
Author(s):  
Rubem Figueiredo Sadok Menna-Barreto ◽  
Solange Lisboa de Castro

The pathogenic trypanosomatidsTrypanosoma brucei,Trypanosoma cruzi, andLeishmaniaspp. are the causative agents of African trypanosomiasis, Chagas disease, and leishmaniasis, respectively. These diseases are considered to be neglected tropical illnesses that persist under conditions of poverty and are concentrated in impoverished populations in the developing world. Novel efficient and nontoxic drugs are urgently needed as substitutes for the currently limited chemotherapy. Trypanosomatids display a single mitochondrion with several peculiar features, such as the presence of different energetic and antioxidant enzymes and a specific arrangement of mitochondrial DNA (kinetoplast DNA). Due to mitochondrial differences between mammals and trypanosomatids, this organelle is an excellent candidate for drug intervention. Additionally, during trypanosomatids’ life cycle, the shape and functional plasticity of their single mitochondrion undergo profound alterations, reflecting adaptation to different environments. In an uncoupling situation, the organelle produces high amounts of reactive oxygen species. However, these species role in parasite biology is still controversial, involving parasite death, cell signalling, or even proliferation. Novel perspectives on trypanosomatid-targeting chemotherapy could be developed based on better comprehension of mitochondrial oxidative regulation processes.


2017 ◽  
Vol 114 (35) ◽  
pp. E7367-E7376 ◽  
Author(s):  
Rene Barro-Soria ◽  
Rosamary Ramentol ◽  
Sara I. Liin ◽  
Marta E. Perez ◽  
Robert S. Kass ◽  
...  

KCNE β-subunits assemble with and modulate the properties of voltage-gated K+ channels. In the heart, KCNE1 associates with the α-subunit KCNQ1 to generate the slowly activating, voltage-dependent potassium current (IKs) in the heart that controls the repolarization phase of cardiac action potentials. By contrast, in epithelial cells from the colon, stomach, and kidney, KCNE3 coassembles with KCNQ1 to form K+ channels that are voltage-independent K+ channels in the physiological voltage range and important for controlling water and salt secretion and absorption. How KCNE1 and KCNE3 subunits modify KCNQ1 channel gating so differently is largely unknown. Here, we use voltage clamp fluorometry to determine how KCNE1 and KCNE3 affect the voltage sensor and the gate of KCNQ1. By separating S4 movement and gate opening by mutations or phosphatidylinositol 4,5-bisphosphate depletion, we show that KCNE1 affects both the S4 movement and the gate, whereas KCNE3 affects the S4 movement and only affects the gate in KCNQ1 if an intact S4-to-gate coupling is present. Further, we show that a triple mutation in the middle of the transmembrane (TM) segment of KCNE3 introduces KCNE1-like effects on the second S4 movement and the gate. In addition, we show that differences in two residues at the external end of the KCNE TM segments underlie differences in the effects of the different KCNEs on the first S4 movement and the voltage sensor-to-gate coupling.


2020 ◽  
Vol 176 ◽  
pp. 104076 ◽  
Author(s):  
Chaoxia Lu ◽  
Zhongtao Feng ◽  
Fang Yuan ◽  
Guoliang Han ◽  
Jianrong Guo ◽  
...  

Gut ◽  
1970 ◽  
Vol 11 (2) ◽  
pp. 126-133 ◽  
Author(s):  
L. A. Turnberg ◽  
G. Grahame

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