GONUTS has been updated to MW1.31 Most things seem to be working but be sure to report problems.

Have any questions? Please email us at ecoliwiki@gmail.com

PMID:10660608

From GONUTS
Jump to: navigation, search
Citation

Uren, A, Reichsman, F, Anest, V, Taylor, WG, Muraiso, K, Bottaro, DP, Cumberledge, S and Rubin, JS (2000) Secreted frizzled-related protein-1 binds directly to Wingless and is a biphasic modulator of Wnt signaling. J. Biol. Chem. 275:4374-82

Abstract

Secreted Frizzled-related protein-1 (sFRP-1) contains a cysteine-rich domain homologous to the putative Wnt-binding site of Frizzleds. To facilitate the biochemical and biological analysis of sFRP-1, we developed a mammalian recombinant expression system that yields approximately 3 mg of purified protein/liter of conditioned medium. Using this recombinant protein, we demonstrated that sFRP-1 and Wg (wingless) interact in enzyme-linked immunosorbent and co-precipitation assays. Surprisingly, a derivative lacking the cysteine-rich domain retained the ability to bind Wg. Cross-linking experiments performed with radioiodinated sFRP-1 provided definitive evidence that sFRP-1 and Wg bind directly to each other. Besides detecting a cross-linked complex consistent in size with 1:1 stoichiometry of sFRP-1 and Wg, we also observed a larger complex whose size suggested the presence of a second sFRP-1 molecule. The formation of both complexes was markedly enhanced by an optimal concentration of exogenous heparin, emphasizing the potential importance of heparan-sulfate proteoglycan in Wnt binding and signaling. sFRP-1 exerted a biphasic effect on Wg activity in an armadillo stabilization assay, increasing armadillo level at low concentrations but reducing it at higher concentrations. These results provide new insights about the Wnt binding and biological activity of sFRPs.

Links

PubMed

Keywords

Animals; Antigens, CD/genetics; Antigens, CD/metabolism; Antigens, CD98; Armadillo Domain Proteins; Binding Sites; Carrier Proteins/genetics; Carrier Proteins/metabolism; Cell Line; Cross-Linking Reagents; Dogs; Drosophila; Drosophila Proteins; Enzyme-Linked Immunosorbent Assay; Heparin/pharmacology; Humans; Insect Proteins/metabolism; Protein Binding; Proto-Oncogene Proteins/metabolism; Recombinant Proteins/metabolism; Signal Transduction; Trans-Activators; Transcription Factors; Wnt Proteins; Wnt1 Protein; Zebrafish Proteins

Significance

Annotations

Gene product Qualifier GO Term Evidence Code with/from Aspect Extension Notes Status

DROME:WNTG

enables

GO:0005515: protein binding

ECO:0000353: physical interaction evidence used in manual assertion

UniProtKB:Q8N474

F

Seeded From UniProt

complete

HUMAN:SFRP1

involved_in

GO:0030178: negative regulation of Wnt signaling pathway

ECO:0000314: direct assay evidence used in manual assertion

P

Seeded From UniProt

complete

HUMAN:SFRP1

involved_in

GO:0030177: positive regulation of Wnt signaling pathway

ECO:0000314: direct assay evidence used in manual assertion

P

Seeded From UniProt

complete

HUMAN:SFRP1

enables

GO:0008201: heparin binding

ECO:0000314: direct assay evidence used in manual assertion

F

Seeded From UniProt

complete

HUMAN:SFRP1

enables

GO:0017147: Wnt-protein binding

ECO:0000353: physical interaction evidence used in manual assertion

UniProtKB:P09615

F

Seeded From UniProt

complete

HUMAN:SFRP1

involved_in

GO:0045893: positive regulation of transcription, DNA-templated

ECO:0000314: direct assay evidence used in manual assertion

P

Seeded From UniProt

complete

HUMAN:SFRP1

involved_in

GO:0045892: negative regulation of transcription, DNA-templated

ECO:0000314: direct assay evidence used in manual assertion

P

Seeded From UniProt

complete


See also

References

See Help:References for how to manage references in GONUTS.