Expression and function of the HNK-1 carbohydrate.
Glycosylation is a major post-translational protein modification, especially for cell surface proteins, which play important roles in a variety of cellular functions, including recognition and adhesion. Among them, we have been interested in HNK-1 (human natural killer-1) carbohydrate, which is characteristically expressed on a series of cell adhesion molecules in the nervous system. The HNK-1 carbohydrate has a unique structural feature, i.e. a sulfated glucuronic acid is attached to the non-reducing terminal of an N-acetyllactosamine residue (HSO(3)-3GlcAbeta1-3Galbeta1-4GlcNAc-). We have cloned and characterized the biosynthetic enzymes (two glucuronyltransferases and a sulfotransferase), and also obtained evidence that the HNK-1 carbohydrate is involved in synaptic plasticity and memory formation. In this review, we describe recent findings regarding the expression mechanism and functional roles of this carbohydrate.
Morita
Ippei
I
Department of Biological Chemistry, Graduate School of Pharmaceutical Sciences, Kyoto University, Kyoto 606-8501, Japan.
Kizuka
Yasuhiko
Y
Kakuda
Shinako
S
Oka
Shogo
S
D000818:Animals; D018959:CD57 Antigens / Q000737:chemistry / Q000502:physiology*; D014453:Glucuronosyltransferase / Q000737:chemistry / Q000378:metabolism; D006801:Humans; D015238:Sulfotransferases / Q000737:chemistry / Q000378:metabolism; D000097811:Carbohydrate Sulfotransferases
D018959:CD57 Antigens; D014453:Glucuronosyltransferase; D015238:Sulfotransferases; C475472:B3GAT2 protein, human; C111364:galactosylgalactoylxylosylprotein 3-beta-glucuronosyltransferase; C499549:CHST10 protein, human; D000097811:Carbohydrate Sulfotransferases