Mitochondrial Ca2+ uptake with and without the formation of high-Ca2+ microdomains

G. Szanda, Péter Koncz, P. Várnai, A. Spät

Research output: Contribution to journalArticle

31 Citations (Scopus)

Abstract

The mitochondrial Ca2+ uniporter has low affinity for Ca2+, therefore it has been assumed that submicromolar Ca2+ signals cannot induce mitochondrial Ca2+ uptake. The close apposition of the plasma membrane or the endoplamic reticulum (ER) to the mitochondria and the limited Ca2+ diffusion in the cytoplasm result in the formation of perimitochondrial high-Ca2+ microdomains (HCMDs) capable of activating mitochondrial Ca2+ uptake. The possibility of mitochondrial Ca2+ uptake at low submicromolar [Ca2+]c has not yet been generally accepted. Earlier we found in permeabilized glomerulosa, luteal and pancreatic β cells that [Ca2+]m increased when [Ca2+]c was raised from 60 nM to less than 200 nM. Here we report data obtained from H295R (adrenocortical) cells transfected with ER-targeted GFP. Cytoplasmic Ca2+ response to angiotensin II was different in mitochondrion-rich and mitochondrion-free domains. The mitochondrial Ca2+ response to angiotensin II correlated with GFP fluorescence indicating the vicinity of ER. When the cells were exposed to K+ (inducing Ca2+ influx), no correlation was found between the mitochondrial Ca2+ signal and the vicinity of the plasma membrane or the ER. The results presented here provide evidence that mitochondrial Ca2+ uptake may occur both with and without the formation of HCMDs within the same cell.

Original languageEnglish
Pages (from-to)527-537
Number of pages11
JournalCell Calcium
Volume40
Issue number5-6
DOIs
Publication statusPublished - Nov 2006

Fingerprint

Reticulum
Mitochondria
Angiotensin II
Cell Membrane
Luteal Cells
Cytoplasm
Fluorescence

Keywords

  • Angiotensin II
  • Ca signal
  • Endoplasmic reticulum
  • Glomerulosa cell
  • H295R cells
  • Microdomains
  • Mitochondria
  • Potassium

ASJC Scopus subject areas

  • Cell Biology
  • Endocrinology

Cite this

Mitochondrial Ca2+ uptake with and without the formation of high-Ca2+ microdomains. / Szanda, G.; Koncz, Péter; Várnai, P.; Spät, A.

In: Cell Calcium, Vol. 40, No. 5-6, 11.2006, p. 527-537.

Research output: Contribution to journalArticle

@article{526f2b5131fc4b8ab911e5192a19e7d2,
title = "Mitochondrial Ca2+ uptake with and without the formation of high-Ca2+ microdomains",
abstract = "The mitochondrial Ca2+ uniporter has low affinity for Ca2+, therefore it has been assumed that submicromolar Ca2+ signals cannot induce mitochondrial Ca2+ uptake. The close apposition of the plasma membrane or the endoplamic reticulum (ER) to the mitochondria and the limited Ca2+ diffusion in the cytoplasm result in the formation of perimitochondrial high-Ca2+ microdomains (HCMDs) capable of activating mitochondrial Ca2+ uptake. The possibility of mitochondrial Ca2+ uptake at low submicromolar [Ca2+]c has not yet been generally accepted. Earlier we found in permeabilized glomerulosa, luteal and pancreatic β cells that [Ca2+]m increased when [Ca2+]c was raised from 60 nM to less than 200 nM. Here we report data obtained from H295R (adrenocortical) cells transfected with ER-targeted GFP. Cytoplasmic Ca2+ response to angiotensin II was different in mitochondrion-rich and mitochondrion-free domains. The mitochondrial Ca2+ response to angiotensin II correlated with GFP fluorescence indicating the vicinity of ER. When the cells were exposed to K+ (inducing Ca2+ influx), no correlation was found between the mitochondrial Ca2+ signal and the vicinity of the plasma membrane or the ER. The results presented here provide evidence that mitochondrial Ca2+ uptake may occur both with and without the formation of HCMDs within the same cell.",
keywords = "Angiotensin II, Ca signal, Endoplasmic reticulum, Glomerulosa cell, H295R cells, Microdomains, Mitochondria, Potassium",
author = "G. Szanda and P{\'e}ter Koncz and P. V{\'a}rnai and A. Sp{\"a}t",
year = "2006",
month = "11",
doi = "10.1016/j.ceca.2006.08.019",
language = "English",
volume = "40",
pages = "527--537",
journal = "Cell Calcium",
issn = "0143-4160",
publisher = "Churchill Livingstone",
number = "5-6",

}

TY - JOUR

T1 - Mitochondrial Ca2+ uptake with and without the formation of high-Ca2+ microdomains

AU - Szanda, G.

AU - Koncz, Péter

AU - Várnai, P.

AU - Spät, A.

PY - 2006/11

Y1 - 2006/11

N2 - The mitochondrial Ca2+ uniporter has low affinity for Ca2+, therefore it has been assumed that submicromolar Ca2+ signals cannot induce mitochondrial Ca2+ uptake. The close apposition of the plasma membrane or the endoplamic reticulum (ER) to the mitochondria and the limited Ca2+ diffusion in the cytoplasm result in the formation of perimitochondrial high-Ca2+ microdomains (HCMDs) capable of activating mitochondrial Ca2+ uptake. The possibility of mitochondrial Ca2+ uptake at low submicromolar [Ca2+]c has not yet been generally accepted. Earlier we found in permeabilized glomerulosa, luteal and pancreatic β cells that [Ca2+]m increased when [Ca2+]c was raised from 60 nM to less than 200 nM. Here we report data obtained from H295R (adrenocortical) cells transfected with ER-targeted GFP. Cytoplasmic Ca2+ response to angiotensin II was different in mitochondrion-rich and mitochondrion-free domains. The mitochondrial Ca2+ response to angiotensin II correlated with GFP fluorescence indicating the vicinity of ER. When the cells were exposed to K+ (inducing Ca2+ influx), no correlation was found between the mitochondrial Ca2+ signal and the vicinity of the plasma membrane or the ER. The results presented here provide evidence that mitochondrial Ca2+ uptake may occur both with and without the formation of HCMDs within the same cell.

AB - The mitochondrial Ca2+ uniporter has low affinity for Ca2+, therefore it has been assumed that submicromolar Ca2+ signals cannot induce mitochondrial Ca2+ uptake. The close apposition of the plasma membrane or the endoplamic reticulum (ER) to the mitochondria and the limited Ca2+ diffusion in the cytoplasm result in the formation of perimitochondrial high-Ca2+ microdomains (HCMDs) capable of activating mitochondrial Ca2+ uptake. The possibility of mitochondrial Ca2+ uptake at low submicromolar [Ca2+]c has not yet been generally accepted. Earlier we found in permeabilized glomerulosa, luteal and pancreatic β cells that [Ca2+]m increased when [Ca2+]c was raised from 60 nM to less than 200 nM. Here we report data obtained from H295R (adrenocortical) cells transfected with ER-targeted GFP. Cytoplasmic Ca2+ response to angiotensin II was different in mitochondrion-rich and mitochondrion-free domains. The mitochondrial Ca2+ response to angiotensin II correlated with GFP fluorescence indicating the vicinity of ER. When the cells were exposed to K+ (inducing Ca2+ influx), no correlation was found between the mitochondrial Ca2+ signal and the vicinity of the plasma membrane or the ER. The results presented here provide evidence that mitochondrial Ca2+ uptake may occur both with and without the formation of HCMDs within the same cell.

KW - Angiotensin II

KW - Ca signal

KW - Endoplasmic reticulum

KW - Glomerulosa cell

KW - H295R cells

KW - Microdomains

KW - Mitochondria

KW - Potassium

UR - http://www.scopus.com/inward/record.url?scp=33751045175&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=33751045175&partnerID=8YFLogxK

U2 - 10.1016/j.ceca.2006.08.019

DO - 10.1016/j.ceca.2006.08.019

M3 - Article

C2 - 17069884

AN - SCOPUS:33751045175

VL - 40

SP - 527

EP - 537

JO - Cell Calcium

JF - Cell Calcium

SN - 0143-4160

IS - 5-6

ER -