Trefoil factor 1

Trefoil factor 1 is a protein that in humans is encoded by the TFF1 gene^[5][6] (also called pS2 gene^[7]).

TFF1
Available structures PDB Ortholog search: PDBe RCSB List of PDB id codes 1HI7, 1PS2
Identifiers
Aliases	TFF1, BCEI, D21S21, HP1.A, HPS2, pNR-2, pS2, trefoil factor 1
External IDs	OMIM: 113710; MGI: 88135; HomoloGene: 2426; GeneCards: TFF1; OMA:TFF1 - orthologs
Gene location (Human) Chr. Chromosome 21 (human)[1] Band 21q22.3 Start 42,362,282 bp[1] End 42,366,535 bp[1]
Gene location (Mouse) Chr. Chromosome 17 (mouse)[2] Band 17 A3.3|17 15.8 cM Start 31,380,369 bp[2] End 31,384,251 bp[2]
RNA expression pattern Bgee Human Mouse (ortholog) Top expressed in pancreatic ductal cell gastric mucosa palpebral conjunctiva pylorus mucosa of sigmoid colon mucosa of ileum gallbladder cardia rectum jejunal mucosa Top expressed in pyloric antrum epithelium of stomach mucous cell of stomach tibiofemoral joint perirhinal cortex entorhinal cortex right ventricle CA3 field Ileal epithelium choroid plexus of fourth ventricle More reference expression data BioGPS More reference expression data
Gene ontology Molecular function growth factor activity protein binding Cellular component extracellular space extracellular region Biological process response to immobilization stress cell differentiation response to peptide hormone maintenance of gastrointestinal epithelium negative regulation of cell population proliferation response to iron ion wound healing carbohydrate metabolic process regulation of signaling receptor activity digestion signal transduction Sources:Amigo / QuickGO
Orthologs Species Human Mouse Entrez 7031 21784 Ensembl ENSG00000160182 ENSMUSG00000024032 UniProt P04155 Q08423 RefSeq (mRNA) NM_003225 NM_009362 RefSeq (protein) NP_003216 NP_033388 Location (UCSC) Chr 21: 42.36 – 42.37 Mb Chr 17: 31.38 – 31.38 Mb PubMed search [3] [4]
Wikidata
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Function

Members of the trefoil family are characterized by having at least one copy of the trefoil motif, a 40-amino acid domain that contains three conserved disulfides. They are stable secretory proteins expressed in gastrointestinal mucosa. Their functions are not defined, but they may protect the mucosa from insults, stabilize the mucus layer, and affect healing of the epithelium. This gene, which is expressed in the gastric mucosa, has also been studied because of its expression in human tumors. This gene and two other related trefoil family member genes are found in a cluster on chromosome 21.^[6]

Glycan binding

All three human trefoil factors are lectins that interact specifically with the disaccharide GlcNAc-α-1,4-Gal.^[8] This disaccharide is an unusual glycotope that is only known to exist on the large, heavily glycosylated, mucins in the mucosa. By cross-linking mucins through the bivalent binding of this glycotope, the trefoil factors are then able to reversibly modulate the thickness and viscosity of the mucus.^[8]

In gastric carcinoma

TFF1 expression is frequently lost in gastric carcinoma, probably through mechanism of DNA methylation, and it is therefore considered as a tumor suppressor gene.^[9]