plasma membrane lactate transport

Definition

Target type: biologicalprocess

The directed movement of lactate across a plasma membrane. [GOC:mcc]

Lactate transport across the plasma membrane is a crucial process involved in various physiological functions, including energy metabolism, pH regulation, and cell signaling. The plasma membrane, which acts as a selective barrier between the cell interior and the extracellular environment, plays a pivotal role in mediating this transport.

Several membrane proteins facilitate lactate transport, with the most prominent being the monocarboxylate transporter (MCT) family. These transporters are integral membrane proteins with 12 transmembrane domains, forming a channel-like structure through which lactate can pass.

The MCT family consists of 14 members, but MCT1, MCT2, and MCT4 are particularly important for lactate transport in various tissues. These transporters exhibit distinct kinetic properties and tissue distribution, contributing to their specialized roles.

MCT1 is ubiquitously expressed and plays a crucial role in basal lactate transport, mediating both influx and efflux. MCT2 is highly expressed in tissues with high metabolic activity, such as the brain and skeletal muscle, primarily mediating lactate uptake. MCT4 is predominantly found in highly glycolytic tissues, such as skeletal muscle and red blood cells, facilitating lactate efflux.

The transport mechanism of MCTs involves a proton-linked co-transport process. Lactate and a proton (H+) bind to the transporter simultaneously, moving across the membrane in the same direction. The proton gradient across the membrane provides the driving force for lactate transport.

Lactate transport across the plasma membrane is tightly regulated by several factors, including substrate concentration, pH, and cellular energy status. These regulatory mechanisms ensure that lactate transport meets the specific demands of different tissues and cellular functions.

The biological significance of plasma membrane lactate transport is multifaceted. In energy metabolism, lactate serves as a substrate for gluconeogenesis in the liver and as a fuel source for certain tissues, such as the heart. In pH regulation, lactate transport plays a critical role in maintaining intracellular pH homeostasis by buffering protons. Additionally, lactate has been implicated in cell signaling pathways, influencing cell growth, differentiation, and immune responses.

In conclusion, plasma membrane lactate transport is a complex and highly regulated process mediated by a family of specialized transporters, primarily the MCTs. This transport plays crucial roles in energy metabolism, pH regulation, and cell signaling, contributing to the overall physiological function of various tissues and organs.'
"

Proteins (2)

Compounds (4)