The eup genetic locus of Escherichia coli and its role in H+/solute symport.

Plate, Charles; Suit, Joan L.

doi:10.1016/s0021-9258(18)42992-4

Cited by 29 publications

(11 citation statements)

References 46 publications

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“…Toward this end, we were aided by the availability of E. coli strain DF877 which is deleted of the rha-pfkA region of the chromosome (Daldal & Fraenkel, 1981). Previously we presented data consistent with the eup locus being located near minute 88 between the markers rha and pfkA (Plate & Suit, 1981;Bachmann, 1983). Thus, a strain having a deletion extending from rha through pfkA should be a eup deletion as well, and such a strain should manifest the effects of the total absence of eup gene product on such a function as active transport.…”

Section: Resultssupporting

confidence: 74%

“…Studies carried out independently in three laboratories have resulted in the identification of a genetic locus in Escherichia coli which has been variously designated eup, ecfB, and ssd (Plate, 1976;Plate & Suit, 1981;Thorbjarnardottir et al, 1978, Morris & Newman et al, 1981. Single-site mutations in this locus result in lowered growth yields on limiting glucose, resistance to aminoglycoside antibiotics, reduced sensitivity to certain colicins (A and K) (Plate, 1976;Luria, 1982), inability to grow on nonfermentable carbon sources, and defective protonmotive force (PMF)-coupled active transport.…”

mentioning

confidence: 99%

“…Single-site mutations in this locus result in lowered growth yields on limiting glucose, resistance to aminoglycoside antibiotics, reduced sensitivity to certain colicins (A and K) (Plate, 1976;Luria, 1982), inability to grow on nonfermentable carbon sources, and defective protonmotive force (PMF)-coupled active transport. Electron transport and ^ATPase hydrolytic activity are not adversely affected by eup mutations (Plate, 1976); neither is the ability to generate and maintain a PMF (Plate & Suit, 1981;Hitchens et al, 1982;Kashket, 1982). This phenotype, along with the finding that a eup mutation results in an apparent uncoupling of proton fluxes from thiomethyl 0-D-galactopyranoside (TMG) and proline fluxes, led us to postulate that the role of the eup gene product is to function in coupling the PMF to the processes driven by it (Plate & Suit, 1981).…”

mentioning

confidence: 99%

“…Electron transport and ^ATPase hydrolytic activity are not adversely affected by eup mutations (Plate, 1976); neither is the ability to generate and maintain a PMF (Plate & Suit, 1981;Hitchens et al, 1982;Kashket, 1982). This phenotype, along with the finding that a eup mutation results in an apparent uncoupling of proton fluxes from thiomethyl 0-D-galactopyranoside (TMG) and proline fluxes, led us to postulate that the role of the eup gene product is to function in coupling the PMF to the processes driven by it (Plate & Suit, 1981).…”

mentioning

confidence: 99%

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Evidence for a protonmotive force related regulatory system in Escherichia coli and its effects on lactose transport

Plate¹,

Seely²,

Laffler³

1986

Biochemistry

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Strains of Escherichia coli with mutations in the eup (energy-uncoupled phenotype) locus do not grow on nonfermentable carbon sources, have reduced growth yields on limiting glucose, are insensitive to colicins A and K, exhibit resistance to aminoglycoside antibiotics, and are defective in protonmotive force coupled active transport. eup mutations do not result in lowered protonmotive force. Here we show that deenergization of a eup+ strain results in the appearance of a new low KT, low Vmax form of the lactose carrier; in a strain deleted of the eup locus, deenergization does not evoke the low KT, low Vmax form of the lactose carrier. Cells bearing a eup point mutation and exhibiting the Eup- phenotype possess the low KT, low Vmax form of the lactose carrier even when energized. In addition to affecting the kinetic parameters of the lactose carrier, the eup point mutation also reduces the KT and Vmax of the proline carrier. On the basis of these findings, we suggest that the normal eup gene product mediates a novel regulation of lactose carrier function following deenergization. The defect in proline and lactose transport caused by eup point mutations may stem from an altered eup product aberrantly mediating the regulation under energized conditions. Finally, the pleiotropy associated with eup point mutations may be indicative of those protonmotive force driven functions that are subject to eup regulation.

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Section: Resultssupporting

confidence: 74%

mentioning

confidence: 99%

mentioning

confidence: 99%

mentioning

confidence: 99%

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Evidence for a protonmotive force related regulatory system in Escherichia coli and its effects on lactose transport

Plate¹,

Seely²,

Laffler³

1986

Biochemistry

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“…It is already known that the uptake of various amino acids across bacterial membrane is driven by a pH gradient (Plate & Suit, 1981). However, until now the stimulation of the L-alanine transport by a pH gradient has not been reported in luminal-membrane vesicles from a mammalian kidney proximal tubule.…”

Section: Discussionmentioning

confidence: 97%

Renal transport of neutral amino acids. Cation-dependent uptake of l-alanine by luminal-membrane vesicles

Jørgensen

Sheikh

1987

Biochemical Journal

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The characteristics of L-alanine transport in luminal-membrane vesicles isolated either from whole cortex or from pars convoluta or pars recta of rabbit proximal tubules were studied by a rapid filtration technique and by a spectrophotometric method. Uptake of L-alanine by vesicles from whole cortex was mediated by both Na+-dependent and Na+-independent, but electrogenic, processes. The nature, mechanism and tubular localization of the transport systems were studied by the use of vesicles derived from pars convoluta and pars recta. In vesicles from pars recta transport of L-alanine was strictly dependent on Na+ and occurred via a dual transport system, namely a high-affinity (half-saturation 0.14 mM) and a low-affinity system (half-saturation 9.6 mM). The cation-dependent but Na+-unspecific transport system for L-alanine was exclusively localized to the pars convoluta, which also contained an Na+-preferring system of intermediate affinity (half saturation 2.1 mM). A closer examination of the mechanism of transport of L-alanine in vesicles from pars convoluta revealed that an H+ gradient (extravesicular greater than intravesicular) can drive the transport of L-alanine into the vesicles both in the presence and in the absence of Na+. The physiological importance of various L-alanine transporters is briefly discussed.

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Active Transport in Escherichia Coli From Membrane to Molecule

Kaback

1986

Physiology of Membrane Disorders

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The eup genetic locus of Escherichia coli and its role in H+/solute symport.

Cited by 29 publications

References 46 publications

Evidence for a protonmotive force related regulatory system in Escherichia coli and its effects on lactose transport

Evidence for a protonmotive force related regulatory system in Escherichia coli and its effects on lactose transport

Renal transport of neutral amino acids. Cation-dependent uptake of l-alanine by luminal-membrane vesicles

Active Transport in Escherichia Coli From Membrane to Molecule

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