MGP Database

New search | Record Overview | Ontology/Pathway Information | Domain Information | UniProt Annotations | Related Proteins
MGP001807

UniProt Annotations

Entry Information
Gene Namelactase
Protein EntryLPH_HUMAN
UniProt IDP09848
SpeciesHuman
Comments
Comment typeDescription
Catalytic ActivityGlycosyl-N-acylsphingosine + H(2)O = N- acylsphingosine + a sugar.
Catalytic ActivityLactose + H(2)O = D-galactose + D-glucose.
DiseaseCongenital lactase deficiency (COLACD) [MIM:223000]: Autosomal recessive, rare and severe gastrointestinal disorder. It is characterized by watery diarrhea in infants fed with breast milk or other lactose-containing formulas. An almost total lack of LCT activity is found in jejunal biopsy material of patients with congenital lactase deficiency. Opposite to congenital lactase deficiency, also known as lactose intolerance, is the most common enzyme deficiency worldwide. It is caused by developmental down- regulation of lactase activity during childhood or early adulthood. The decline of lactase activity is a normal physiological phenomenon; however, the majority of Northern Europeans have the ability to maintain lactase activity and digest lactose throughout life (lactase persistence). The down-regulation of lactase activity operates at the transcriptional level and it is associated with a noncoding variation in the MCM6 gene, located in the upstream vicinity of LCT. {ECO:0000269|PubMed:16400612}. Note=The disease is caused by mutations affecting the gene represented in this entry.
DomainThe sequence exhibits 4 regions (I-IV) of internal homology; therefore LPH might have evolved by two cycles of partial gene duplication.
FunctionLPH splits lactose in the small intestine.
SimilarityBelongs to the glycosyl hydrolase 1 family. {ECO:0000305}.
Subcellular LocationApical cell membrane; Single-pass type I membrane protein. Note=Brush border.
Tissue SpecificityIntestine.
Web ResourceName=Protein Spotlight; Note=Darwin's dessert - Issue 111 of November 2009; URL="http://web.expasy.org/spotlight/back_issues/111";
Web ResourceName=Wikipedia; Note=Lactase entry; URL="http://en.wikipedia.org/wiki/Lactase";
  logo