InnateDB: Systems Biology of the Innate Immune Response

Homo sapiens Protein: SI

Summary

InnateDB Protein

IDBP-63765.6

Last Modified

2014-10-13 [Report errors or provide feedback]

Gene Symbol

Protein Name

sucrase-isomaltase (alpha-glucosidase)

Synonyms

Species

Homo sapiens

Ensembl Protein

ENSP00000264382

InnateDB Gene

IDBG-63763 (SI)

Protein Structure

UniProt Annotation

Function

Plays 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:0000269PubMed:20356844}.

Subcellular Localization

Apical cell membrane; Single-pass type II membrane protein. Note=Brush border.

Disease Associations

Congenital 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:0000269PubMed:10903344, ECO:0000269PubMed:11340066, ECO:0000269PubMed:14724820, ECO:0000269PubMed:16329100, ECO:0000269PubMed:8609217}. Note=The disease is caused by mutations affecting the gene represented in this entry.

Tissue Specificity

Expressed 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:0000269PubMed:1677636}.

Comments

Interactions

Number of Interactions

This gene and/or its encoded proteins are associated with 0 experimentally validated interaction(s) in this database.

Gene Ontology

Molecular Function

Accession	GO Term
GO:0003824	catalytic activity
GO:0004553	hydrolase activity, hydrolyzing O-glycosyl compounds
GO:0004558	alpha-glucosidase activity
GO:0004574	oligo-1,6-glucosidase activity
GO:0004575	sucrose alpha-glucosidase activity
GO:0030246	carbohydrate binding

Biological Process

GO:0005975	carbohydrate metabolic process
GO:0044245	polysaccharide digestion
GO:0044281	small molecule metabolic process

Cellular Component

GO:0005794	Golgi apparatus
GO:0005886	plasma membrane
GO:0005903	brush border
GO:0016020	membrane
GO:0016021	integral component of membrane
GO:0016324	apical plasma membrane

Protein Structure and Domains

PDB ID

InterPro

IPR000322 Glycoside hydrolase, family 31
IPR000519 P-type trefoil
IPR011013 Galactose mutarotase-like domain
IPR017853 Glycoside hydrolase, superfamily

PFAM

PF01055
PF00088

PRINTS

PIRSF

SMART

SM00018

TIGRFAMs

Post-translational Modifications

Modification

Cross-References

SwissProt

P14410