Identification and characterization of high-affinity Ca2+-ATPase associated with axonal plasma membranes of dog mesenteric nerves

1990 ◽  
Vol 15 (8) ◽  
pp. 833-841 ◽  
Author(s):  
Peter Kostka ◽  
William H. Barnett ◽  
Chiu-Yin Kwan
Biochemistry ◽  
1991 ◽  
Vol 30 (44) ◽  
pp. 10738-10745 ◽  
Author(s):  
Michel Hugues ◽  
Marlys Crane ◽  
Shereen Hakki ◽  
Peter O'Hanley ◽  
Scott A. Waldman

2013 ◽  
Vol 288 (20) ◽  
pp. 14428-14437 ◽  
Author(s):  
Marco A. Sanchez

Pyruvate export is an essential physiological process for the bloodstream form of Trypanosoma brucei as the parasite would otherwise accumulate this end product of glucose metabolism to toxic levels. In the studies reported here, genetic complementation in Saccharomyces cerevisiae has been employed to identify a gene (TbPT0) that encodes this vital pyruvate transporter from T. brucei. Expression of TbPT0 in S. cerevisiae reveals that TbPT0 is a high affinity pyruvate transporter. TbPT0 belongs to a clustered multigene family consisting of five members, whose expression is up-regulated in the bloodstream form. Interestingly, TbPT family permeases are related to polytopic proteins from plants but not to characterized monocarboxylate transporters from mammals. Remarkably, inhibition of the TbPT gene family expression in bloodstream parasites by RNAi is lethal, confirming the physiological relevance of these transporters. The discovery of TbPT0 reveals for the first time the identity of the essential pyruvate transporter and provides a potential drug target against the mammalian life cycle stage of T. brucei.


1979 ◽  
Vol 92 (3) ◽  
pp. 512-521 ◽  
Author(s):  
B. Czarnocka ◽  
J. Nauman ◽  
G. Adler ◽  
W. Kiełczyński

ABSTRACT Crude plasma membranes obtained from bovine thyroids were found to possess one class of high affinity, low capacity binding sites for TSH with average association constant (Ka) of 1.301 × 109 m−1 and maximal capacity 8.76 × 10−10 m/mg of protein. Treatment of crude membranes fraction with 0.1 % Triton X-100 and the subsequent sonication in ultrasonic disintegrator resulted in solubilization of membranes proteins with mean recovery of 40.0 ± 6.2 %. Soluble proteins retained the property to bind [125I]TSH, but the binding of the hormone was decreased. The removal of the detergent from the solubilizate by gel filtration on Sephadex LH-20 increased the binding of TSH well above that demonstrated for crude thyroid membranes. The chromatography of soluble proteins on Ultrogel AcA-44 revealed the presence of two TSH binding proteins, one with the molecular weight (m.w.) above 130 000 daltons and the other with the m.w. approximately 30 000 daltons. The electrofocusing of solubilizate on Ampholine resulted in two protein peaks, one at pH 4.0–4.1 and the other at pH 4.4–4.6. The latter peak was shown to bind [125I]TSH specifically. The present results have confirmed the heterogeneous character of solubilized TSH receptor preparation and have shown that the hormone binding sites belong to acid proteins.


1998 ◽  
Vol 53 (3-4) ◽  
pp. 141-150 ◽  
Author(s):  
Thorsten Nürnberger ◽  
Dirk Nennstiel

Abstract Highly sensitive and specific recognition systems for microbial pathogens are essential for disease resistance in plants. Proteinaceous elicitors activating plant pathogen defense have been identified in numerous antagonistic plant/fungus interactions. Precisely defined signal structures required for elicitor-mediated activation of plant defense are indicative of the involvement of receptors in elicitor perception and subsequent signal generation. Use of pure elicitor preparations has helped to establish a functional link between binding of elicitors to high-affinity binding sites in plant plasma membranes and activation of plant defense. Thus elicitor binding sites appear to function as physiological receptors. Currently, isolation and molecular characterization of elicitor receptors is under way. Transfer of new recognition specificities into plants is supposed to be a key strategy for engineering pathogen resistance in economically important crops.


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