Other amino acid transport systems

Other amino acid transport systems refers to a heterogeneous group of membrane transport proteins, primarily within the Solute Carrier (SLC) superfamily, that mediate the uptake and efflux of amino acids across cellular and organelle membranes. This classification typically includes systems such as System A (SLC38 family), System L (SLC7 family), System N, and System ASC, which are distinguished by their substrate preferences, ion dependencies, and transport mechanism (Alexander et al., 2021). These transporters are fundamental to cellular physiology, as they provide the necessary precursors for protein synthesis, maintain osmotic balance, and regulate metabolic signaling pathways such as the mechanistic target of rapamycin (mTOR) (Bröer, 2008). In various diseases, particularly cancer, these transporters are frequently dysregulated; for instance, the L-type amino acid transporter 1 (LAT1/SLC7A5) is often overexpressed in malignant cells to sustain rapid growth and proliferation (Kandasamy et al., 2018). Consequently, these systems are significant therapeutic targets, either through direct inhibition to starve tumor cells or by exploiting them as 'Trojan horses' for the delivery of amino acid-mimetic drugs like melphalan and levodopa (Häfliger & Charles, 2019). Mutations in these transport systems are also associated with hereditary conditions such as Hartnup disease and cystinuria, highlighting their critical role in systemic amino acid homeostasis.

Other names

Amino acid transportersSolute carrier amino acid transportersSLC transportersSystem ASystem LSystem NSystem ASC

Competitive inhibition of amino acid transport or utilization as a transport vehicle for prodrug delivery.