Human Gene LCT (ENST00000264162.7) from GENCODE V44
Description: Homo sapiens lactase (LCT), mRNA. (from RefSeq NM_002299) RefSeq Summary (NM_002299): The protein encoded by this gene belongs to the glycosyl hydrolase 1 family of proteins. The encoded preproprotein is proteolytically processed to generate the mature enzyme. This enzyme is integral to the plasma membrane and has both phlorizin hydrolase activity and lactase activity. Mutations in this gene are associated with congenital lactase deficiency. Polymorphisms in this gene are associated with lactase persistence, in which intestinal lactase activity persists at childhood levels into adulthood. [provided by RefSeq, Jan 2016]. Gencode Transcript: ENST00000264162.7 Gencode Gene: ENSG00000115850.10 Transcript (Including UTRs) Position: hg38 chr2:135,787,850-135,837,184 Size: 49,335 Total Exon Count: 17 Strand: - Coding Region Position: hg38 chr2:135,788,324-135,837,169 Size: 48,846 Coding Exon Count: 17
ID:LPH_HUMAN DESCRIPTION: RecName: Full=Lactase-phlorizin hydrolase; AltName: Full=Lactase-glycosylceramidase; Includes: RecName: Full=Lactase; EC=3.2.1.108; Includes: RecName: Full=Phlorizin hydrolase; EC=3.2.1.62; Flags: Precursor; FUNCTION: LPH splits lactose in the small intestine. CATALYTIC ACTIVITY: Lactose + H(2)O = D-galactose + D-glucose. CATALYTIC ACTIVITY: Glycosyl-N-acylsphingosine + H(2)O = N- acylsphingosine + a sugar. SUBCELLULAR LOCATION: Apical cell membrane; Single-pass type I membrane protein. Note=Brush border. TISSUE SPECIFICITY: Intestine. DOMAIN: The sequence exhibits 4 regions (I-IV) of internal homology; therefore LPH might have evolved by two cycles of partial gene duplication. DISEASE: Defects in LCT are the cause of congenital lactase deficiency (COLACD) [MIM:223000]; also known as hereditary alactasia or disaccharide intolerance II. Congenital lactase deficiency is a an 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, adult-type hypolactasia, 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. SIMILARITY: Belongs to the glycosyl hydrolase 1 family. WEB RESOURCE: Name=GeneReviews; URL="http://www.ncbi.nlm.nih.gov/sites/GeneTests/lab/gene/LCT"; WEB RESOURCE: Name=Wikipedia; Note=Lactase entry; URL="http://en.wikipedia.org/wiki/Lactase"; WEB RESOURCE: Name=Protein Spotlight; Note=Darwin's dessert - Issue 111 of November 2009; URL="http://web.expasy.org/spotlight/back_issues/sptlt111.shtml";
The RNAfold program from the Vienna RNA Package is used to perform the secondary structure predictions and folding calculations. The estimated folding energy is in kcal/mol. The more negative the energy, the more secondary structure the RNA is likely to have.
Pfam Domains: PF00232 - Glycosyl hydrolase family 1
ModBase Predicted Comparative 3D Structure on P09848
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Orthologous Genes in Other Species
Orthologies between human, mouse, and rat are computed by taking the best BLASTP hit, and filtering out non-syntenic hits. For more distant species reciprocal-best BLASTP hits are used. Note that the absence of an ortholog in the table below may reflect incomplete annotations in the other species rather than a true absence of the orthologous gene.
US Server
