title: Developmentally and spatially regulated expression of HNK-1 carbohydrate antigen on a novel phosphatidylinositol-anchored glycoprotein in rat brain.
abstract: HNK-1 carbohydrate antigen in an epitope expressed commonly in many cell surface adhesion and recognition molecules in the nervous system. We purified and characterized from rat brain a novel phosphatidylinositol (PI)-anchored 150-kD glycoprotein belonging to the HNK-1 family. The molecule (PI-GP150) was detected by combination of PI-specific phospholipase C treatment of brain membranes and Western blot analysis with mAb HNK-1. HNK-1-positive PI-GP150 was purified from the PI-PLC-released materials with three successive chromatographies (Sephacryl S-300, mAb HNK-1-Sepharose 4B, and Mono Q) and proven to be a novel molecule by immunoblot and structural analyses. Polyclonal antibody was raised against PI-GP150 and used to show that (a) PI-GP150 is expressed on the surface of neuronal cell bodies and their processes in culture, and (b) PI-GP150 appears during embryonic development and is present throughout all postnatal life in all brain regions. However, the expression of the HNK-1 epitope on PI-GP150 is regulated in both developmental stage-specific and region-specific manners. In newborn rats, the HNK-1 epitope is expressed on PI-GP150 throughout the brain. The level of HNK-1 epitope on PI-GP150 decreases after postnatal day 7 in hindbrain and becomes completely absent in adult myelencephalon and metencephalon. In contrast, HNK-1 epitope on PI-GP150 was constitutively expressed in telencephalon. Thus, while the HNK-1 carbohydrate epitope is strongly coupled to PI-GP150, its expression can be regulated independently of that of PI-GP150. The differential expression of the HNK-1 epitope at different rostro-caudal axial levels was observed also in other HNK-1 family molecules in brain membranes. These results suggest that the HNK-1 epitope plays an important role in adding region-specific and developmental stage-specific modifications on the function of the cell surface molecules.
authors.affiliation: Department of Neuroscience, Osaka Bioscience Institute, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Yoshihara
authors.forename: S
authors.initials: S
authors.lastname: Oka
authors.forename: Y
authors.initials: Y
authors.lastname: Watanabe
authors.forename: K
authors.initials: K
authors.lastname: Mori
mesh_terms: D000375:Aging; D000818:Animals; D000906:Antibodies; D000943:Antigens, Differentiation / Q000235:genetics* / Q000302:isolation & purification; D001921:Brain / Q000196:embryology / Q000254:growth & development*; D018959:CD57 Antigens; D004622:Embryo, Mammalian; D000939:Epitopes / Q000032:analysis; D005455:Fluorescent Antibody Technique; D015870:Gene Expression; D005865:Gestational Age; D006017:Glycolipids / Q000502:physiology*; D006023:Glycoproteins / Q000302:isolation & purification / Q000502:physiology*; D017261:Glycosylphosphatidylinositols; D007425:Intracellular Membranes / Q000502:physiology; D009474:Neurons / Q000502:physiology*; D009928:Organ Specificity; D010716:Phosphatidylinositols / Q000502:physiology*; D051381:Rats; D011919:Rats, Inbred Strains; D013574:Synaptosomes / Q000502:physiology; D010738:Type C Phospholipases / Q000378:metabolism
chemical_list: D000906:Antibodies; D000943:Antigens, Differentiation; D018959:CD57 Antigens; D000939:Epitopes; D006017:Glycolipids; D006023:Glycoproteins; D017261:Glycosylphosphatidylinositols; D010716:Phosphatidylinositols; D010738:Type C Phospholipases