GLUT1GLUT14

GLUT1GLUT14 refers to the family of glucose transporter proteins in humans known as GLUT1 through GLUT14, encoded by the genes SLC2A1–SLC2A14. These proteins belong to the solute carrier 2 (SLC2) family and function as facilitative transporters that mediate the passive movement of glucose and, in some cases, related hexoses across cellular membranes along concentration gradients. All members share a common architecture of multiple transmembrane helices and operate via alternating outward- and inward-facing conformations to allow substrate passage, with notable differences in substrate affinity and tissue distribution.

The best characterized members illustrate diverse physiological roles. GLUT1 (SLC2A1) is widely expressed and supports basal glucose uptake in many tissues, including the blood–brain barrier and erythrocytes. GLUT3 (SLC2A3) is enriched in neurons and exhibits high glucose affinity. GLUT2 (SLC2A2) functions as a low-affinity, high-capacity transporter in liver, pancreatic beta cells, kidney, and intestine, aiding glucose sensing and homeostasis. GLUT4 (SLC2A4) is insulin-responsive in adipose tissue and skeletal muscle, linking glucose uptake to metabolic state. GLUT5 (SLC2A5) primarily transports fructose. The remaining GLUT family members, including less characterized isoforms such as GLUT12, GLUT13, and GLUT14 (SLC2A14), show more restricted or poorly defined expression patterns, with GLUT14 described as a relatively recently described paralog in humans and evidence for its transport activity and physiological role continues to emerge.

Clinical and research relevance: disordered expression or function of GLUTs is implicated in diseases ranging from GLUT1 deficiency syndrome to cancer metabolism. Ongoing studies aim to clarify tissue-specific roles, regulatory mechanisms, and therapeutic potential across the GLUT1GLUT14 family.