Gellerich 2009 PLoS One

Gellerich FN, Gizatullina Z, Arandarcikaite O, Jerzembek D, Vielhaber S, Seppet E, Striggow F (2009) Extramitochondrial Ca2+ in the nanomolar range regulates glutamate-dependent oxidative phosphorylation on demand. PloS One 4:e8181.

» PMID: 20011041 Open Access

Gellerich FN, Gizatullina Z, Arandarcikaite O, Jerzembek D, Vielhaber S, Seppet E, Striggow F (2009) PLoS One

Abstract: We present unexpected and novel results revealing that glutamate-dependent oxidative phosphorylation (OXPHOS) of brain mitochondria is exclusively and efficiently activated by extramitochondrial Ca²⁺ in physiological concentration ranges (S_0.5= 360 nM Ca²⁺). This regulation was not affected by RR, an inhibitor of the mitochondrial Ca²⁺ uniporter. Active respiration is regulated by glutamate supply to mitochondria via aralar, a mitochondrial glutamate/aspartate carrier with regulatory Ca²⁺-binding sites in the mitochondrial intermembrane space providing full access to cytosolic Ca²⁺. At micromolar concentrations, Ca²⁺ can also enter the intramitochondrial matrix and activate specific dehydrogenases. However, the latter mechanism is less efficient than extramitochondrial Ca²⁺ regulation of respiration/OXPHOS via aralar. These results imply a new mode of glutamate-dependent OXPHOS regulation as a demand-driven regulation of mitochondrial function. This regulation involves the mitochondrial glutamate/aspartate carrier aralar which controls mitochondrial substrate supply according to the level of extramitochondrial Ca²⁺. • Keywords: Glutamate/aspartate carrier aralar, Extramitochondrial Ca (2+), Brain mitochondria

• O2k-Network Lab: EE_Tartu Paju K, DE Magdeburg Gellerich FN

Labels: MiParea: Respiration 

Tissue;cell: Nervous system 

Enzyme: Inner mt-membrane transporter  Regulation: Calcium, Inhibitor  Coupling state: OXPHOS 

HRR: Oxygraph-2k 

Ca-list