Calcium transport in membrane vesicles of <i>Streptococcus cremoris</i>

Driessen, Arnold J. M.; Konings, Wil N.

doi:10.1111/j.1432-1033.1986.tb09845.x

Cited by 20 publications

(8 citation statements)

References 38 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The sodium ATPase is known to be inducible (12,13), but the Na+/H+ antiporter appears to be constitutive. The existence of dual systems has been suggested for calcium extrusion in streptococci (2,11).…”

Section: Discussionmentioning

confidence: 99%

Sodium/proton antiporter in Streptococcus faecalis

Kakinuma¹

1987

J Bacteriol

View full text Add to dashboard Cite

Streptococcusfaecalis, like other bacteria, accumulates potassium ions and expels sodium ions. This paper is concerned with the pathway of sodium extrusion. Earlier studies (D. L. Heefner and F. M. Harold, Proc. Natl. Acad. Sci. USA 79:2798-2802, 1982) showed that sodium extrusion is effected by a primary, ATP-linked sodium pump. I report here that cells grown under conditions in which sodium ATPase is not induced can still expel sodium ions. This finding suggested the existence of an alternate pathway. Sodium extrusion by the alternate pathway requires the cells to generate a proton motive force. This conclusion rests on the following observations. (i) Sodium extrusion required glucose. (ii) Sodium extrusion was observed at neutral pH, which allows the cells to generate a proton motive force, but not at alkaline pH, which reduces the proton motive force to zero. (iii) Sodium extrusion was inhibited by the addition of dicyclohexylcarbodiimide and of protonconducting ionophores. (iv) In response to an artificial pH gradient (with the exterior acid), energy-depleted cells exhibited a transient sodium extrusion which was unaffected by treatments that dissipated the membrane potential and which was blocked by proton conductors. I propose that streptococci have two independent systems for sodium extrusion: an inducible sodium ATPase and a constitutive sodium/proton antiporter.The significance of sodium circulation for the physiology of bacteria is well recognized (4,17,18,21). Growing bacterial cells extrude sodium ions actively and maintain a sodium concentration gradient directed inward. Sodium extrusion by bacteria is generally attributed to secondary antiport of sodium for protons, which is energized by the proton motive force (3,17,19). The sodium gradient serves as a driving force for transport systems catalyzing sodium/ substrate symport (18). In addition, sodium/proton antiporters are thought to be involved in the regulation of the cytoplasmic pH (17,20).From earlier studies of sodium extrusion by Streptococcus faecalis, Harold and his collaborators concluded that streptococci expel Na+ by means of an ATP-driven primary pump that exchanges sodium ions for protons (8)(9)(10). Heefner and Harold also demonstrated sodium/proton antiport activity in both cells and membrane vesicles, but they regarded this activity as an artifact arising from proteolytic damage to the ATPase (7, 9). They suggested that the ATPase is composed of two subunits, i.e., a Na+/H+ antiporter and an associated catalytic subunit. Damage to this modular pump could alter the association of the subunits, resulting in the appearance of sodium/proton antiport activity (7, 9, 10).Subsequent research on the sodium ATPase led me to question the view that S. faecalis has only a single system for sodium extrusion and that the Na+/H+ antiport activity arises by proteolytic damage to the sodium ATPase. In a study of potassium accumulation via the KtrII system of S. faecalis, Kakinuma and Harold found that the system responsible for potassium accumulat...

show abstract

Section: Discussionmentioning

confidence: 99%

Sodium/proton antiporter in Streptococcus faecalis

Kakinuma¹

1987

J Bacteriol

View full text Add to dashboard Cite

show abstract

“…cremoris ). This organism possesses only one transport system which catalyzes the translocation of Ile, Leu, Met, and Val in symport with one H + (Driessen et al 1987c). Several streptococci (Moran 1980;Akpemado & Bracquart 1983;Trombe et al 1984;Dashper & Reynolds 1993), Lb.…”

Section: Transport Of Branched-chain Amino Acidsmentioning

confidence: 97%

“…However, it has been shown that the expression of the gene clusters plpABCD-ydcBCD, encoding the putative Met ABC transporter is under control of the sulphur transcriptional regulator CmbR (Sperandio et al 2005). In addition, Met can be transported by the pmf driven branched chain amino acid carrier of L. lactis, albeit it shows low affinity for Met (Driessen et al 1987c). Also, little is known about Cys transport in LAB.…”

Section: Transport Of Cys and Metmentioning

confidence: 98%

Amino Acid Catabolic Pathways of Lactic Acid Bacteria

Fernández

Zúñiga

2006

Critical Reviews in Microbiology

341

229

View full text Add to dashboard Cite

Lactic acid bacteria (LAB) constitute a diverse group of Gram positive obligately fermentative microorganisms which include both beneficial and pathogenic strains. LAB generally have complex nutritional requirements and therefore they are usually associated with nutrient-rich environments such as animal bodies, plants and foodstuffs. Amino acids represent an important resource for LAB and their utilization serves a number of physiological roles such as intracellular pH control, generation of metabolic energy or redox power, and resistance to stress. As a consequence, the regulation of amino acid catabolism involves a wide set of both general and specific regulators and shows significant differences among LAB. Moreover, due to their fermentative metabolism, LAB amino acid catabolic pathways in some cases differ significantly from those described in best studied prokaryotic model organisms such as Escherichia coli or Bacillus subtilis. Thus, LAB amino acid catabolism constitutes an interesting case for the study of metabolic pathways. Furthermore, LAB are involved in the production of a great variety of fermented products so that the products of amino acid catabolism are also relevant for the safety and the quality of fermented products.

show abstract

“…It is the process favored for microbial boring by Garcia-Pichel (2006) for a variety of reasons, including that the microbes are capable of boring into calcium phosphate substrates where organic acids would be less effective in causing dissolution. (2) The Ca 2+ would be transported actively through the cell and ejected through the cell membrane on the other side of the microbe in exchange for protons utilizing calcium-proton exchanging ATPase (e.g., Driessen and Konings, 1986). Such polarization at a cellular level has been documented previously in cyanobacteria (Sherman et al, 1994).…”

Section: Age Of Borings and Mode Of Formationmentioning

confidence: 95%