The sodium ion translocating adenosine triphosphatase of Propionigenium modestum pumps protons at low sodium ion concentrations

Biochemistry ◽  
1989 ◽  
Vol 28 (18) ◽  
pp. 7194-7198 ◽  
Author(s):  
Werner Laubinger ◽  
Peter Dimroth
1960 ◽  
Vol 198 (5) ◽  
pp. 1019-1022 ◽  
Author(s):  
Samuel Mallov

Rats were rendered hypertensive by injecting DCA and feeding 1% NaCl solution in place of drinking water. Isometric tensions developed by strips of aorta from these rats, when exposed to a low concentration of epinephrine, were compared with tensions developed by strips from normotensive controls, under conditions of varying Na ion concentration and solution tonicity. Solutions with high Na ion concentrations (hypertonic), and normal solutions rendered equivalently hypertonic by the addition of sucrose, increased the reactivities of strips from normotensive rats, but decreased the reactivities of strips from hypertensive rats, to added epinephrine. The hypertensive rat strips manifested increases in tension in these solutions even prior to the addition of epinephrine, so that the subsequent smaller responses to epinephrine may have been related to these initial tension increases. Low sodium ion concentrations in hypotonic solutions, but not in isotonic solutions, decreased the reactivities of both hypertensive and normotensive rat strips. These results are interpreted to mean that aortas from hypertensive rats are so changed structurally and functionally, that they respond differently than do normal aortas to increased sodium ion concentrations and/or hypertonic solutions, as well as to epinephrine in such solutions.


Biochemistry ◽  
1990 ◽  
Vol 29 (23) ◽  
pp. 5458-5463 ◽  
Author(s):  
Werner Laubinger ◽  
Gabriele Deckers-Hebestreit ◽  
Karlheinz Altendorf ◽  
Peter Dimroth

2006 ◽  
Vol 74 (3) ◽  
pp. 1725-1740 ◽  
Author(s):  
Caterina Monaco ◽  
Adelfia Talà ◽  
Maria Rita Spinosa ◽  
Cinzia Progida ◽  
Eleanna De Nitto ◽  
...  

ABSTRACT GdhR is a meningococcal transcriptional regulator that was previously shown to positively control the expression of gdhA, encoding the NADP-specific l-glutamate dehydrogenase (NADP-GDH), in response to the growth phase and/or to the carbon source. In this study we used reverse transcriptase-PCR-differential display (to identify additional GdhR-regulated genes. The results indicated that GdhR, in addition to NADP-GDH, controls the expression of a number of genes involved in glucose catabolism by the Entner-Doudoroff pathway and in l-glutamate import by an unknown ABC transport system. The genes encoding the putative periplasmic substrate-binding protein (NMB1963) and the permease (NMB1965) of the ABC transporter were genetically inactivated. Uptake experiments demonstrated an impairment of l-glutamate import in the NMB1965-defective mutant in the absence or in the presence of a low sodium ion concentration. In contrast, at a sodium ion concentration above 60 mM, the uptake defect disappeared, possibly because the activity of a sodium-driven secondary transporter became predominant. Indeed, the NMB1965-defective mutant was unable to grow at a low sodium ion concentration (<20 mM) in a chemically defined medium containing l-glutamate and four other amino acids that supported meningococcal growth, but it grew when the sodium ion concentration was raised to higher values (>60 mM). The same growth phenotype was observed in the NMB1963-defective mutant. Cell invasion and intracellular persistence assays and expression data during cell invasion provided evidence that the l-glutamate ABC transporter, tentatively named GltT, was critical for meningococcal adaptation in the low-sodium intracellular environment.


1990 ◽  
Vol 193 (2) ◽  
pp. 395-399 ◽  
Author(s):  
Wolfgang LUDWIG ◽  
Georg KAIM ◽  
Werner LAUBINGER ◽  
Peter DIMROTH ◽  
Jurgen HOPPE ◽  
...  

1972 ◽  
Vol 11 (3) ◽  
pp. 669-673
Author(s):  
K. JOBST ◽  
N. KELLERMAYER

In HeLa cells cultured in a medium containing 142 mequiv./l. sodium ions only the mitotic forms are birefringent (anisotropic index, 27/1000). In a culture medium containing 155-160 mequiv./l. sodium ions, large numbers of nuclear forms reminiscent of the prophase were found. In such a medium the anisotropic index was 86/1000. At low sodium ion concentration (90-110 mequiv./l.) these anomalous, prophase-like forms were not seen and the anisotropic index was 18/1000. The appearance of the birefringent, prophase-like forms is related to a structural rearrangement and condensation of DNP in a hypertonic medium.


1996 ◽  
Vol 138 (2) ◽  
pp. 219-230 ◽  
Author(s):  
Richard D. Storer ◽  
Lea R. Gordon ◽  
John Barnum ◽  
Keith Soper ◽  
Chennekatu P. Peter

Sign in / Sign up

Export Citation Format

Share Document