HAMES_DBI.A1

 Sodium Glucose Transport 1 (P13866)

    The digestive system has a host of biomolecules that perform various functions and aid in digestion and absorption. One of these amazing molecules in the digestive system is the protein, sodium glucose transport 1 (SGLT1), but other names include high infinity sodium-glucose cotransporter, and solute carrier family 5 member 1. SGLT1 is an important protein that mediates and regulates sugars across cell membranes found in humans. The gene that encodes this protein is SLC5A1. These proteins are mainly present in the tissues of the kidney and small intestine. Subcellularly, these proteins can be found mainly in endosomes, apical cell membranes, between cells in cell-cell junctions, and some are found in the extracellular spaces outside of cells through secretion. SGLT1 is used in sodium coupling and is involved in cotransport of sugars and sodium in the kidney proximal tubules. SGLT1 transports sodium and glucose at a ratio of 2:1 respectively. The protein cotransporter is driven by the basolateral sodium/potassium-ATPase to transport sodium across the concentration gradient out of the cell, meanwhile transporting glucose and other sugars across the cell membrane into cell. Specifically, SGLT1 transports alpha-glucoside, D-glucose, fucose, galactose, glucose, pentose, and also water. This protein is very important in the regulation of sugars in the intestines and the kidney, as well as some reabsorption of filtered glucose (along with SGLT2). This protein, as well as its counterpart SGLT2, help to ensure that sugars and nutrients are absorbed into the bloodstream and not released as urine. Both proteins are involved in research for diabetes and possible inhibitors of the protein to help regulate blood sugar levels in the body. These proteins play a vital role in homeostasis, leading to lots of research into their involvement in possibly being able to cure different diseases. A point of research is the disease that is heavily related to the protein, congenital glucose/galactose malabsorption (GGM). It is a rare metabolic, recessive disease that only affects about 300 people in the world. This disease is caused by variants of the gene SLC5A1, the same gene that is responsible for encoding SGLT1. When the gene mutates, the enzyme driving the co-transportation isn't able to work properly, not allowing for the absorption of simple sugars into the intestines. Due to the inability to absorb sugars in the small intestine, the sugars are excreted in the stool because they have nowhere else to go. As a result, the sugars draw large amounts of water and leads to lots of diarrhea and dehydration. This autosomal recessive disorder typically manifests within the first few weeks of life and is usually fatal, unless glucose and galactose are eliminated completely from the diet. SGLT1 is vital to the absorption of sugars and homeostasis in the kidney, intestines, digestive system, and the body as a whole. 

 Citations

The UniProt Consortium

UniProt: the universal protein knowledgebase in 2021

https://www.uniprot.org/uniprot/P13866. Accessed February 2, 2022. 

The US National Library of Medicine Institutes of  Health https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5364028/. Accessed February 2, 2022.