Binding Proteins and Membrane Transport

Carafoli, Ernesto; Crompton, Martin

doi:10.1007/978-1-4684-2658-8_8

Cited by 13 publications

(12 citation statements)

References 165 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In the presence of 3 mM-Tris/phosphate and mM-MgCl2 there was no consistent difference but without the Mg2+ the uptake was slower in NaCl, in agreement with Carafoli & Crompton (1976).…”

Section: Externalsupporting

confidence: 82%

The uptake and release of calcium by heart mitochondria

Harris

1977

Biochemical Journal

View full text Add to dashboard Cite

The kinetics of uptake of Ca2+ by rat heart mitochondria were studied by a spectrophotometric method with Arsenazo III indicator. The exponential rate coefficients measured with or without added phosphate increase with the amount of Ca2+ added up to about 24pM. Evidence is given that the effect is attributable to a combination of formation of chelates at low concentrations to act as C2+ buffers, with co-transport of substrate to provide more respiratory fuel. The inhibitory effect of Mg2+ depends on the Ca2+ concentration, so with a constant [Mg2+] the low concentrations of Ca2+ are most inhibited, and the rate coefficients are still more Ca2+-dependent. Ca2+ uptake is slowed by local anaesthetics such as butacaine and dibucaine, and also by propranolol and palmitoyl-CoA.After an uptake, the release of Ca2+ was investigated. The spontaneous release involves an initially slow and small appearance of free Ca2+ and is followed by an auto-accelerated phase. The release is accompanied by a gradual decrease in internal ATP; it is initiated by palmitoyl-CoA (reversed by carnitine), by lysophosphatidylcholine, by Na+ salts (reversed by oligomycin) and by K+ salts added to a K+-free medium containing valinomycin. The process is probably a response to an increased energy load imposed on the mitochondria by the various conditions, which include the spontaneous action ofphospholipase activated by traces of Ca2+. The problem of how much mitochondrial activity is participating in normal heart Ca2+ turnover is discussed, and experiments showing only 7-14 % exchange of the, mitochondrial Ca2+ occurring in vivo in 10 or 20min are reported.

show abstract

“…In the presence of 3 mM-Tris/phosphate and mM-MgCl2 there was no consistent difference but without the Mg2+ the uptake was slower in NaCl, in agreement with Carafoli & Crompton (1976).…”

Section: Externalsupporting

confidence: 82%

The uptake and release of calcium by heart mitochondria

Harris

1977

Biochemical Journal

View full text Add to dashboard Cite

show abstract

“…In these circumstances it is dangerous to ignore the possibility that the reagents used (e.g., insulin, glucagon, prostaglandins) could have affected Ca*+ availability in the cells and that the true mitogenic effects resulted from Ca2' action. Insulin [9, 36,68], glucagon [69], and prostaglandins [70] are all known to affect cell membranes, ion transport and Ca*" availability in cells [48]. Furthermore cyclic AMP-elevating agents other than cholera toxin are not always effective in assisting growth [71].…”

Section: Is Cyclic Amp a Mitogen?mentioning

confidence: 99%

Cyclic AMP, calcium and control of cell growth

Ralph

1983

FEBS Letters

View full text Add to dashboard Cite

The role of cyclic AMP and calcium in the control of normal and tumour cell growth is considered in relation to the question whether cyclic AMP is a true mitogen or cc-mitogen. It is proposed that cyclic AMP normally controls the cell cycle at a point in Gl phase only by virtue of its ability to exclude calcium required by cells to progress past this point into S phase. Therefore increased influx of calcium by other routes induced by various factors can bypass the inhibitory effect of cyclic AMP and stimulate growth. In these circumstances cyclic AMP or calcium may or may not facilitate further progress into S phase according to the metabolic requirements of individual cells. The relevance to cancer cells is considered. Cyclic AMP Calcium

show abstract

“…Ca" uptake is abolished by 3 FM ruthenium red which, within seconds, induces a release of sequestered Ca2+ indicative of a high rate of Ca'+-cycling across the inner membrane of these mitochondria. The lack of a discernible effect of Na+ upon the rate of Ca2+ efflux suggests that unlike brown adipose tissue ~t~hon~a, a Na+-induced Ca2+-efflux mechanism may not operate in mitochondria from white adipocytes (review [29] observed at 1%20pM free Ca2+, A similar high affinity for Ca2' has been observed in rat liver mitochondria in the absence of added Mg2+ [30] and in ~tochondria isolated from a variety of other tissues and species [9]. The presence of 2 mM Mg2+ or of 1 mM ATP reduced the initial rate of Ca2+ transport by -5OVo (not shown).…”

Section: -Bmentioning

confidence: 86%

Characterisation of Ca²⁺ transport activity by white adipose tissue mitochondria

1983

View full text Add to dashboard Cite

Ca2' transport in mitochondria isolated from rat white adipocytes has been examined and many of the properties found to be similar to those reported for mitochondria isolated from rat liver. Ca" transport is ruthenium red-sensitive (Ki -5 pmol . mg protein-'), the affinity for free Ca2' is high (Km -3.3 PM) and the V,, is 135 nmol Ca2+ .min-'.mg protein-' at 4°C with 0.2 mM Pi present. Ca" transport is stimulated by increasing the medium [Pi], and is inhibited when ATP or Mg2+ is added to the incubation system and in contrast to brown adipocyte mitochondria, Ca2' efflux is not promoted by Na+. White adipocyte mitochondria may play a role in the regulation of total cell calcium in this tissue. Calcium-transport

show abstract

Binding Proteins and Membrane Transport

Cited by 13 publications

References 165 publications

The uptake and release of calcium by heart mitochondria

The uptake and release of calcium by heart mitochondria

Cyclic AMP, calcium and control of cell growth

Characterisation of Ca²⁺ transport activity by white adipose tissue mitochondria

Contact Info

Product

Resources

About

Binding Proteins and Membrane Transport

Cited by 13 publications

References 165 publications

The uptake and release of calcium by heart mitochondria

The uptake and release of calcium by heart mitochondria

Cyclic AMP, calcium and control of cell growth

Characterisation of Ca2+ transport activity by white adipose tissue mitochondria

Contact Info

Product

Resources

About

Characterisation of Ca²⁺ transport activity by white adipose tissue mitochondria