C1GALT1-specific chaperone 1 (IPR026731)

Short name: C1GALT1C1

Overlapping homologous superfamilies


Family relationships



C1GALT1-specific chaperone 1 (C1GALT1C1) is a probable chaperone required for the generation of 1 O-glycan Gal-beta1-3GalNAc-alpha1-Ser/Thr (T antigen), which is a precursor for many extended O-glycans in glycoproteins. It probably acts as a specific molecular chaperone assisting the folding/stability of core 1 beta-3-galactosyltransferase (C1GALT1) [PMID: 12464682].

Defects in C1GALT1C1 are the cause of Tn syndrome (TNSYN). Tn syndrome is a rare autoimmune disease caused by somatic mutation in the C1GALT1C1 gene in which subpopulations of blood cells of all lineages carry an incompletely glycosylated membrane glycoprotein, i.e., the Tn antigen. Since leukocytes and platelets are affected as well as red cells, anemia, leukopenia and thrombocytopenia are features. Tn-polyagglutinability is sometimes associated with leukemia or is a preleukemic state [PMID: 17038624].

It's worth noting that C1GALT1C1 was originally assigned to be a glycosyltransferase. However, it was later shown [PMID: 12361956] that it has no transferase activity and rather acts as a chaperone [PMID: 12464682].

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.