SLC5A1 Protein, Human (HEK293, His)

SLC5A1 is an electrogenic Na(+)-coupled sugar symporter that actively transports D-glucose or D-galactose at the plasma membrane, with a Na(+) to sugar coupling ratio of 2:1. Its transporter activity is driven by a transmembrane Na(+) electrochemical gradient established by the Na(+)/K(+) pump. It primarily functions in transporting dietary monosaccharides from enterocytes to the blood, facilitating the absorption of D-glucose or D-galactose across the apical brush-border membrane of enterocytes, while basolateral exit is mediated by GLUT2. Additionally, it acts as a D-glucose sensor in enteroendocrine cells, triggering the secretion of incretins GCG and GIP, which regulate food intake and energy homeostasis (By similarity). Alongside SGLT2, it participates in the reabsorption of D-glucose from glomerular filtrate, playing a nonredundant role in the S3 segment of proximal tubules (By similarity). It also transports D-glucose into endometrial epithelial cells, supporting glycogen synthesis, embryonic nutrition, and decidual transformation of the endometrium prior to conception. Furthermore, it functions as a water channel, enabling passive water transport in response to osmotic gradients created by sugar and Na(+) uptake, with high water conductivity comparable to aquaporins, suggesting a key role in transepithelial water permeability, particularly in the small intestine.