*608043
UDP-N-ACETYL-ALPHA-D-GALACTOSAMINE:POLYPEPTIDE N-ACETYLGALACTOSAMINYLTRANSFERASE 10; GALNT10

Alternative titles; symbols
GalNAc TRANSFERASE 10; GalNAcT10

HGNC Approved Gene Symbol: GALNT10

Cytogenetic location: 5q33.2     Genomic coordinates (GRCh37): 5:153,570,294 - 153,800,543 (from NCBI)

TEXT
Description
Polypeptide GalNAc transferases (GalNAcTs; EC 2.4.1.41), such as GALNT10, initiate the synthesis of mucin-type oligosaccharides by transferring GalNAc from UDP-GalNAc to the hydroxyl group of either a serine or threonine residue on the polypeptide acceptor.

Cloning
By searching an EST database for sequences similar to GALNT7 (605005), followed by PCR of colon cancer cell line cDNA, Cheng et al. (2002) cloned GALNT10, which they called GalNAcT10. The deduced type II membrane protein contains 603 amino acids. Its catalytic domain has conserved motifs for the binding of a UDP-sugar and an acceptor, and its C terminus has a lectin-like domain characteristic of GalNAcTs. GALNT10 shares 94% homology with rat GalNAcT9. Real-time PCR detected expression in all tissues tested, with highest levels in small intestine and intermediate levels in stomach, pancreas, ovary, thyroid gland, and spleen. Little to no expression was observed in other normal tissues and in most tumor cell lines examined.

Gene Function
Cheng et al. (2002) analyzed the biochemical activity of recombinant GALNT10 expressed in insect cells. GALNT10 showed significant GalNAcT activity toward mucin-derived peptides, and it utilized both nonglycosylated and glycosylated peptide substrates. Using an acceptor substrate containing 7 potential O-glycosylation sites, Cheng et al. (2002) determined that GALNT10 transferred the first GalNAc to thr or ser less efficiently than subsequent transfers, which occurred immediately following the initial GalNAc modification.

Mapping
The International Radiation Hybrid Mapping Consortium mapped the GALNT10 gene to chromosome 5 (stSG35519).

REFERENCES
1. Cheng, L., Tachibana, K., Zhang, Y., Guo, J., Tachibana, K. K., Kameyama, A., Wang, H., Hiruma, T., Iwasaki, H., Togayachi, A., Kudo, T., Narimatsu, H. Characterization of a novel human UDP-GalNAc transferase, pp-GalNAc-T10. FEBS Lett. 531: 115-121, 2002. [PubMed: 12417297, related citations] [Full Text: Elsevier Science, Pubget]

Creation Date: Patricia A. Hartz : 8/15/2003
Edit History: mgross : 08/15/2003