Glutamate-anaplerotic pathway control state

high-resolution terminology - matching measurements at high-resolution

Glutamate-anaplerotic pathway control state

Description

G: Glutamate is an anaplerotic NADH-linked type 4 substrate (N). When supplied as the sole fuel substrate in the glutamate pathway control state, G is transported by the electroneutral glutamate-/OH- exchanger, and is oxidised via mt-glutamate dehydrogenase in the mitochondrial matrix. The G-pathway plays an important role in glutaminolysis.

Abbreviation: G

Reference: Gnaiger 2014 MitoPathways - Chapter 3.3

MitoPedia concepts: SUIT state 

Communicated by Gnaiger E 2016-01-25, edited 2016-11-29.

G(L)

LEAK state (L) with G alone as substrate can be evaluated in the following SUIT protocol:

• SUIT-007

• DL-Protocol for permeabilized cells (pce): SUIT-007 O2 ce-pce D030

G(P)

OXPHOS state (P) with G alone as substrate can be evaluated in the following SUIT protocol:

• SUIT-007

• DL-Protocol for permeabilized cells (pce): SUIT-007 O2 ce-pce D030

G(E)

ET state (E) with G alone as substrate can be evaluated in the following SUIT protocol:

• SUIT-007

• DL-Protocol for permeabilized cells (pce): SUIT-007 O2 ce-pce D030

Details

In human skeletal muscle mitochondria, OXPHOS capacity with glutamate alone (G_P) is 50% to 85% of respiration in the GM pathway control state (GM_P). Accumulation of fumarate inhibits succinate dehydrogenase and glutamate dehydrogenase.

Glutaminolysis: Glutamate derived from hydrolyzation of glutamine is an important aerobic substrate in cultured cells, supporting anaplerosis. Mitochondrial glutamate dehydrogenase is particularly active in astrocytes, preventing glutamate-induced neurotoxicity.

Anaplerosis from malate: mtNAD-malic enzyme supports an anaplerotic pathway when carbohydrate is limiting.

SUITbrowser question: Glutamine/glutamate

The SUITbrowser can be used to find the best SUIT protocols to analyse glutamine/glutamate metabolism, among other research questions.