106 research outputs found
Direct Observation of ATP-Induced Conformational Changes in Single P2X4 Receptors
The ATP-gated P2X4 receptor is a cation channel, which is important in various pathophysiological events. The architecture of the P2X4 receptor in the activated state and how to change its structure in response to ATP binding are not fully understood. Here, we analyze the architecture and ATP-induced structural changes in P2X4 receptors using fast-scanning atomic force microscopy (AFM). AFM images of the membrane-dissociated and membrane-inserted forms of P2X4 receptors and a functional analysis revealed that P2X4 receptors have an upward orientation on mica but lean to one side. Time-lapse imaging of the ATP-induced structural changes in P2X4 receptors revealed two different forms of activated structures under 0 Ca2+ conditions, namely a trimer structure and a pore dilation-like tripartite structure. A dye uptake measurement demonstrated that ATP-activated P2X4 receptors display pore dilation in the absence of Ca2+. With Ca2+, the P2X4 receptors exhibited only a disengaged trimer and no dye uptake was observed. Thus our data provide a new insight into ATP-induced structural changes in P2X4 receptors that correlate with pore dynamics
P2X7 receptor: Death or life?
The P2X7 plasma membrane receptor is an intriguing molecule that is endowed with the ability to kill cells, as well as to activate many responses and even stimulate proliferation. Here, the authors give an overview on the multiplicity and complexity of P2X7-mediated responses, discussing recent information on this receptor. Particular attention has been paid to early and late signs of apoptosis and necrosis linked to activation of the receptor and to the emerging field of P2X7 function in carcinogenesis
Low incidence of SARS-CoV-2, risk factors of mortality and the course of illness in the French national cohort of dialysis patients
Survey on Substrate Specificity with Regard to ATP Analogs of Aminoacyl-tRNA Synthetases from E. coli
Lysyl-tRNA synthetase from yeast. Discrimination of amino acids by native and phosphorylated species
Threonyl-tRNA synthetase from yeast Discrimination of 19 amino acids in aminoacylation of tRNAThr-C-C-A and tRNAThr-C-C-A(2'NH2).
Isoleucyl-tRNA synthetase from baker's yeast. Discrimination of 20 amino acids in aminoacylation of tRNAIle-C-C-3'dA; role of terminal hydroxyl groups in aminoacylation of tRNAIle-C-C-A
Isoleucyl-tRNA synthetase from baker's yeast and from Escherichia coli MRE 600. Discrimination of 20 amino acids in aminoacylation of tRNAIle-C-C-A
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