FAM20B is a kinase that phosphorylates xylose in the glycosaminoglycan–protein linkage region

2009 ◽  
Vol 421 (2) ◽  
pp. 157-162 ◽  
Author(s):  
Toshiyasu Koike ◽  
Tomomi Izumikawa ◽  
Jun-Ichi Tamura ◽  
Hiroshi Kitagawa
Keyword(s):  
Rna Interference ◽  
Heparan Sulfate ◽  
Chondroitin Sulfate ◽  
Hela Cells ◽  
Unknown Function ◽  
Gel Filtration ◽  
Transfected Cells ◽  
Linkage Region ◽  
Xylose Residue ◽  
Weak Similarity

2-O-phosphorylation of xylose has been detected in the glycosaminoglycan–protein linkage region, GlcAβ1-3Galβ1-3Galβ1-4Xylβ1-O-Ser, of proteoglycans. Recent mutant analyses in zebrafish suggest that xylosyltransferase I and FAM20B, a protein of unknown function that shows weak similarity to a Golgi kinase encoded by four-jointed, operate in a linear pathway for proteoglycan production. In the present study, we identified FAM20B as a kinase that phosphorylates the xylose residue in the linkage region. Overexpression of FAM20B increased the amount of both chondroitin sulfate and heparan sulfate in HeLa cells, whereas the RNA interference of FAM20B resulted in a reduction of their amount in the cells. Gel-filtration analysis of the glycosaminoglycan chains synthesized in the overexpressing cells revealed that the glycosaminoglycan chains had a similar length to those in mock-transfected cells. These results suggest that FAM20B regulates the number of glycosaminoglycan chains by phosphorylating the xylose residue in the glycosaminoglycan–protein linkage region of proteoglycans.

scholarly journals Identification of an extended N-acetylated sequence adjacent to the protein-linkage region of fibroblast heparan sulphate

1987 ◽  
Vol 242 (2) ◽  
pp. 493-498 ◽  
Author(s):  
M Lyon ◽  
W P Steward ◽  
I N Hampson ◽  
J T Gallagher
Keyword(s):  
Nitrous Acid ◽  
Random Sequence ◽  
Heparan Sulphate ◽  
Gel Filtration ◽  
Heparan Sulphate Proteoglycan ◽  
Linkage Region ◽  
Xylose Residue ◽  
Sepharose 4B ◽  
Adult Human Skin ◽  
Hydrolysis Of

The distribution of N-sulphate groups within fibroblast heparan sulphate chains was investigated. The detergent-extractable heparan sulphate proteoglycan from adult human skin fibroblasts, radiolabelled with [3H]glucosamine and [35S]sulphate, was coupled to CNBr-activated Sepharose 4B. After partial depolymerization of the heparan sulphate with nitrous acid, the remaining Sepharose-bound fragments were removed by treatment with alkali. These fragments, of various sizes, but all containing an intact reducing xylose residue, were fractionated on Sephacryl S-300 and the distribution of the 3H and 35S radiolabels was analysed. A decreased degree of sulphation was observed towards the reducing termini of the chains. After complete nitrous acid hydrolysis of the Sepharose-bound proteoglycan, analysis of the proximity of N-sulphation to the reducing end revealed the existence of an extended N-acetylated sequence directly adjacent to the protein-linkage sequence. The size of this N-acetylated domain was estimated by gel filtration to be approximately eight disaccharide units. This domain appears to be highly conserved, being present in virtually all the chains derived from this proteoglycan, implying the existence of a mechanism capable of generating such a non-random sequence during the post-polymeric modification of heparan sulphate. Comparison with the corresponding situation in heparin suggests that different mechanisms regulate polymer N-sulphation in the vicinity of the protein-linkage region of these chemically related glycosaminoglycans.

scholarly journals Human Xylosyltransferase II Is Involved in the Biosynthesis of the Uniform Tetrasaccharide Linkage Region in Chondroitin Sulfate and Heparan Sulfate Proteoglycans

2006 ◽  
Vol 282 (8) ◽  
pp. 5201-5206 ◽  
Author(s):  
Claudia Pönighaus ◽  
Michael Ambrosius ◽  
Javier Carrera Casanova ◽  
Christian Prante ◽  
Joachim Kuhn ◽  
...  
Keyword(s):  
Heparan Sulfate ◽  
Chondroitin Sulfate ◽  
Heparan Sulfate Proteoglycans ◽  
Linkage Region

scholarly journals Involvement of chondroitin sulfate synthase-3 (chondroitin synthase-2) in chondroitin polymerization through its interaction with chondroitin synthase-1 or chondroitin-polymerizing factor

2007 ◽  
Vol 403 (3) ◽  
pp. 545-552 ◽  
Author(s):  
Tomomi Izumikawa ◽  
Toru Uyama ◽  
Yuka Okuura ◽  
Kazuyuki Sugahara ◽  
Hiroshi Kitagawa
Keyword(s):  
Rna Interference ◽  
Chondroitin Sulfate ◽  
Chain Length ◽  
Hela Cells ◽  
Polymerase Activity

Previously, we have demonstrated that co-expression of ChSy-1 (chondroitin synthase-1), with ChPF (chondroitin-polymerizing factor) resulted in a marked augmentation of glycosyltransferase activities and the expression of the chondroitin polymerase activity of ChSy-1. These results prompted us to evaluate the effects of co-expression of the recently cloned CSS3 (chondroitin sulfate synthase-3) with ChPF, because ChSy-1 and CSS3 have similar properties, i.e. they possess GalNAcT-II (N-acetylgalactosaminyltransferase-II) and GlcAT-II (glucuronyltransferase-II) activities responsible for the elongation of CS (chondroitin sulfate) chains but cannot polymerize chondroitin chains by themselves. Co-expressed CSS3 and ChPF showed not only substantial GalNAcT-II and GlcAT-II activities but also chondroitin polymerase activity. Interestingly, co-expressed ChSy-1 and CSS3 also exhibited polymerase activity. The chain length of chondroitin formed by the co-expressed proteins in various combinations was different. In addition, interactions between any two of ChSy-1, CSS3 and ChPF were demonstrated by pull-down assays. Moreover, overexpression of CSS3 increased the amount of CS in HeLa cells, while the RNA interference of CSS3 resulted in a reduction in the amount of CS in the cells. Altogether these results suggest that chondroitin polymerization is achieved by multiple combinations of ChSy-1, CSS3 and ChPF. Based on these characteristics, we have renamed CSS3 ChSy-2 (chondroitin synthase-2).

scholarly journals Inhibition of Bcl-2 expression by a novel tumor-specific RNA interference system increases chemosensitivity to 5-fluorouracil in Hela cells

2006 ◽  
Vol 27 (2) ◽  
pp. 242-248 ◽  
Author(s):  
Sheng-lin HUANG ◽  
Yi WU ◽  
Hai YU ◽  
Ping ZHANG ◽  
Xing-qian ZHANG ◽  
...  
Keyword(s):  
Rna Interference ◽  
Hela Cells ◽  
Interference System

RNA interference targeting CML66, a novel tumor antigen, inhibits proliferation, invasion and metastasis of HeLa cells

2008 ◽  
Vol 269 (1) ◽  
pp. 127-138 ◽  
Author(s):  
Qingfei Wang ◽  
Meixing Li ◽  
Ying Wang ◽  
Yong Zhang ◽  
Shu Jin ◽  
...  
Keyword(s):  
Rna Interference ◽  
Hela Cells ◽  
Tumor Antigen ◽  
Invasion And Metastasis

scholarly journals RNA Interference of Human Papillomavirus Type 18 E6 and E7 Induces Senescence in HeLa Cells

2003 ◽  
Vol 77 (10) ◽  
pp. 6066-6069 ◽  
Author(s):  
Allison H. S. Hall ◽  
Kenneth A. Alexander
Keyword(s):  
Cell Proliferation ◽  
Human Papillomavirus ◽  
Rna Interference ◽  
Hela Cells ◽  
Tumor Suppressors ◽  
Small Interfering Rna ◽  
Promote Cell Proliferation ◽  
E6 And E7 ◽  
Cellular Dna ◽  
Interfering Rna

ABSTRACT The human papillomavirus oncoproteins E6 and E7 promote cell proliferation and contribute to carcinogenesis by interfering with the activities of cellular tumor suppressors. We used a small interfering RNA molecule targeting the E7 region of the bicistronic E6 and E7 mRNA to induce RNA interference, thereby reducing expression of E6 and E7 in HeLa cells. RNA interference of E6 and E7 also inhibited cellular DNA synthesis and induced morphological and biochemical changes characteristic of cellular senescence. These results demonstrate that reducing E6 and E7 expression is sufficient to cause HeLa cells to become senescent.

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