lactate:proton symporter activity

Definition

Target type: molecularfunction

Enables the transfer of a solute or solutes from one side of a membrane to the other according to the reaction: lactate (out) + H+ (out) = lactate (in) + H+ (in). [TC:2.A.14.1.1]

Lactate:proton symporter activity refers to the transport of lactate and protons across a biological membrane. This process is crucial for maintaining cellular energy balance, particularly in conditions of high lactate production. The symporter protein binds both lactate and protons simultaneously, facilitating their coupled movement across the membrane. This co-transport mechanism ensures that lactate and protons are transported in the same direction, typically from an area of high concentration to an area of low concentration. The symporter's activity is driven by the proton motive force, which is the electrochemical gradient across the membrane. This gradient is generated by the difference in proton concentration and electrical potential between the two sides of the membrane. When protons move down their electrochemical gradient, they provide the energy required to transport lactate against its concentration gradient. The lactate:proton symporter is essential for several cellular processes, including: * **Lactate removal from muscle cells**: During strenuous exercise, muscle cells produce large amounts of lactate as a byproduct of anaerobic metabolism. The lactate:proton symporter removes lactate from muscle cells and transports it to other tissues, such as the liver, where it can be converted back to glucose. * **Lactate uptake in the liver**: The liver utilizes the lactate:proton symporter to take up lactate from the bloodstream and convert it to glucose through gluconeogenesis. This process is essential for maintaining blood glucose levels during fasting or prolonged exercise. * **Lactate transport in the brain**: The lactate:proton symporter facilitates the transport of lactate across the blood-brain barrier, providing an alternative energy source for brain cells. * **Regulation of pH**: The symporter activity also contributes to the regulation of intracellular pH by removing protons from the cytoplasm. This helps to maintain the optimal pH range for cellular processes. In summary, the lactate:proton symporter plays a crucial role in maintaining cellular energy balance, regulating pH, and transporting lactate between different tissues. Its activity is essential for various physiological functions, including muscle metabolism, glucose homeostasis, and brain function.'
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Proteins (2)

Compounds (20)