MGP Database

New search | Record Overview | Ontology/Pathway Information | Domain Information | UniProt Annotations | Related Proteins
MGP002829

UniProt Annotations

Entry Information
Gene Namesucrase-isomaltase (alpha-glucosidase)
Protein EntrySUIS_HUMAN
UniProt IDP14410
SpeciesHuman
Comments
Comment typeDescription
Catalytic ActivityHydrolysis of (1->6)-alpha-D-glucosidic linkages in some oligosaccharides produced from starch and glycogen by alpha-amylase, and in isomaltose.
Catalytic ActivityHydrolysis of sucrose and maltose by an alpha- D-glucosidase-type action.
DiseaseCongenital sucrase-isomaltase deficiency (CSID) [MIM:222900]: Autosomal recessive intestinal disorder that is clinically characterized by fermentative diarrhea, abdominal pain, and cramps upon ingestion of sugar. The symptoms are the consequence of absent or drastically reduced enzymatic activities of sucrase and isomaltase. The prevalence of CSID is 0.02 % in individuals of European descent and appears to be much higher in Greenland, Alaskan, and Canadian native people. CSID arises due to post-translational perturbations in the intracellular transport, polarized sorting, aberrant processing, and defective function of SI. {ECO:0000269|PubMed:10903344, ECO:0000269|PubMed:11340066, ECO:0000269|PubMed:14724820, ECO:0000269|PubMed:16329100, ECO:0000269|PubMed:8609217}. Note=The disease is caused by mutations affecting the gene represented in this entry.
FunctionPlays an important role in the final stage of carbohydrate digestion. Isomaltase activity is specific for both alpha-1,4- and alpha-1,6-oligosaccharides. {ECO:0000269|PubMed:20356844}.
MiscellaneousThere is a high degree of homology between the isomaltase and sucrase portions (41% of amino acid identity) indicating that this protein is evolved by partial gene duplication.
PtmSulfated. {ECO:0000250}.
PtmThe precursor is proteolytically cleaved when exposed to pancreatic proteases in the intestinal lumen.
SimilarityBelongs to the glycosyl hydrolase 31 family. {ECO:0000305}.
SimilarityContains 2 P-type (trefoil) domains. {ECO:0000255|PROSITE-ProRule:PRU00779}.
Subcellular LocationApical cell membrane; Single-pass type II membrane protein. Note=Brush border.
SubunitThe resulting sucrase and isomaltase subunits stay associated with one another in a complex by non-covalent linkages. {ECO:0000269|PubMed:20356844}.
Tissue SpecificityExpressed in the poorly differentiated crypt cells of the small intestine as well as in the mature villous cells. Expressed at very low levels in the colon. {ECO:0000269|PubMed:1677636}.
  logo