UDP-N-acetyl-alpha-D-galactosamine:polypeptide N-acetylgalactosaminyltransferase (GalNAc-T; EC 2.4.1.41 ) transfers an N-acetyl galactosamine (GalNAc) to a serine or threonine residue in the first step of O-linked oligosaccharide biosynthesis.
NCBI Summary:
This gene encodes a member of the UDP-N-acetyl-alpha-D-galactosamine:polypeptide N-acetylgalactosaminyltransferase (GalNAc-T) family of enzymes. GalNAc-Ts initiate mucin-type O-linked glycosylation in the Golgi apparatus by catalyzing the transfer of GalNAc to serine and threonine residues on target proteins. They are characterized by an N-terminal transmembrane domain, a stem region, a lumenal catalytic domain containing a GT1 motif and Gal/GalNAc transferase motif, and a C-terminal ricin/lectin-like domain. GalNAc-Ts have different, but overlapping, substrate specificities and patterns of expression. Transcript variants derived from this gene that utilize alternative polyA signals have been described in the literature.
General function
Enzyme
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Cellular localization
Cytoplasmic
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Ovarian function
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Expression regulated by
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Ovarian localization
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Cheng L, et al 2002 reported that a novel member of the human UDP-N-acetyl-D-galactosamine:polypeptide N-acetylgalactosaminyltransferase (pp-GalNAc-T) gene family was cloned as a homolog of human pp-GalNAc-T7, and designated pp-GalNAc-T10. pp-GalNAc-T10 transcript was found in the small intestine, stomach, pancreas, ovary, thyroid gland and spleen. In a polypeptide GalNAc-transfer assay, recombinant pp-GalNAc-T10 transferred GalNAc onto a panel of mucin-derived peptide substrates. Furthermore, pp-GalNAc-T10 demonstrated strong transferase activity with glycopeptide substrates.