K-glypican: a novel GPI-anchored heparan sulfate proteoglycan that is highly expressed in developing brain and kidney.
Glypicans are a family of glycosylphosphatidylinositol (GPI)-anchored cell surface heparan sulfate proteoglycans (HSPGs). The glypican family, which currently includes glypican, the developmentally regulated rat intestinal transcript OCI-5, and cerebroglycan, is characterized by a similar core protein size and almost complete conservation of cysteine residues. By RT-PCR using degenerate oligonucleotide primers based on the sequence homologies, we isolated mouse cDNA encoding a novel member of the glypican family as well as mouse homologues of glypican and OCI-5. The novel molecule, named K-glypican, has a predicted molecular mass of 57.5 kD and potential attachment sites for heparan sulfate chains and a GPI anchor in its COOH-terminal region, like other members of the glypican family. Transfection of an epitope-tagged full-length K-glypican cDNA into MDCK cells demonstrated that K-glypican is indeed expressed as a GPI-anchored HSPG. Northern blot analyses with K-glypican, glypican, and OCI-5 probes demonstrated that kidney and developing brain, and that these three molecules show remarkable patterns of cell type- and developmental stage-specific expression. In situ hybridization revealed that the major sites of K-glypican expression in developing embryo are tubular epithelial cells in the kidney and proliferating neuroepithelial cells in the brain. These results indicate that K-glypican is a novel GPI-anchored HSPG involved in embryonic development.
Watanabe
K
K
Cancer Research Center, La Jolla Cancer Research Foundation, California 92037, USA.
Yamada
H
H
Yamaguchi
Y
Y
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D001921:Brain / Q000196:embryology*; D001923:Brain Chemistry / Q000502:physiology; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000032:analysis; D004285:Dogs; D018507:Gene Expression Regulation, Developmental / Q000502:physiology; D015723:Gene Library; D017261:Glycosylphosphatidylinositols / Q000302:isolation & purification; D019812:Heparan Sulfate Proteoglycans; D006497:Heparan Sulfate / Q000235:genetics* / Q000302:isolation & purification; D006801:Humans; D017403:In Situ Hybridization; D007668:Kidney / Q000737:chemistry / Q000196:embryology*; D051379:Mice; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D011509:Proteoglycans / Q000235:genetics* / Q000302:isolation & purification; D012333:RNA, Messenger / Q000032:analysis
D018076:DNA, Complementary; D017261:Glycosylphosphatidylinositols; D019812:Heparan Sulfate Proteoglycans; D006497:Heparan Sulfate; D011509:Proteoglycans; D012333:RNA, Messenger