SGLT1

Sodium/glucose cotransporter 1
Identifiers
Symbol	?
HGNC	11039
OMIM	182380
RefSeq	NM_000343
UniProt	P13866
Search for Structures Swiss-model Domains InterPro

Sodium/glucose cotransporter 1 (SGLT1) is a protein that in humans is encoded by the SLC5A1 gene. SGLT1 is a member of the sodium-glucose transport proteins family, which are responsible for the active transport of glucose and galactose across the apical membrane of the intestinal epithelial cells and the renal proximal tubule.

Structure

SGLT1 is a transmembrane protein that consists of 664 amino acids. It is characterized by 14 transmembrane helices, which facilitate its function as a transporter. The protein is primarily expressed in the small intestine and the kidney, where it plays a crucial role in the absorption of glucose and galactose.

Function

SGLT1 functions as a symporter, meaning it simultaneously transports sodium ions (Na+) and glucose or galactose molecules into the cell. This process is driven by the sodium gradient established by the Na+/K+ ATPase pump, which maintains a low intracellular sodium concentration. The energy from the sodium gradient is used to transport glucose against its concentration gradient, allowing for efficient absorption even when glucose concentrations are low in the intestinal lumen.

Clinical Significance

Mutations in the SLC5A1 gene can lead to a rare genetic disorder known as glucose-galactose malabsorption. This condition is characterized by severe diarrhea and dehydration in infants, as the inability to absorb glucose and galactose leads to osmotic imbalances in the intestine. Management of this condition involves a diet free of glucose and galactose.

SGLT1 is also a target for therapeutic interventions in diabetes mellitus. Inhibitors of SGLT1, along with SGLT2 inhibitors, are being explored for their potential to lower blood glucose levels by reducing intestinal glucose absorption and increasing renal glucose excretion.

Research

Recent studies have focused on the role of SGLT1 in cardiovascular health and its potential involvement in heart failure. The expression of SGLT1 in the heart and its contribution to cardiac glucose uptake is an area of active investigation.

Also see

• Sodium-glucose transport proteins
• SGLT2
• Glucose-galactose malabsorption
• Na+/K+ ATPase
• Diabetes mellitus