Dataset Information

Proximity labeling by a recombinant APEX2-FGF1 fusion protein reveals interaction of FGF1 with the proteoglycans CD44 and CSPG4

ABSTRACT: Fibroblast growth factor 1 (FGF1) binds to specific FGF receptors (FGFRs) at the surface of target cells to initiate intracellular signaling. In addition, FGF1 also binds to heparan sulfate proteoglycans (HSPG), which act as important co-receptors. Even if some interactions with HSPGs have been characterized, it is not entirely clear if FGF1 could interact with additional proteoglycans at the cell surface. We have devised and tested a method to identify novel binding sites for FGF1 at the cell surface, which may also be applicable for other protein ligands. First, we constructed an APEX2-FGF1 fusion protein to perform proximal biotin labeling of proteins after binding of the fusion protein to cells. After functional validation of the construct, we used this method to identify binding sites for FGF1 on living cells. We confirmed the feasibility of our approach by easy detection of FGFR4, a well-known and specific receptor for FGF1. We then performed a screen in RPE1 cells and among the top hits were the proteoglycans CSPG4 (NG2) and CD44. We found that FGF1 binds CD44 through its heparin-binding moiety. Moreover, we found that FGF1 co-localizes with both CSPG4 and CD44 at the cell surface suggesting that these receptors act as storage molecules creating a reservoir of FGF1. Importantly, our data demonstrate that recombinant ligand-APEX2 fusion proteins can be used to identify novel receptor interactions at the cell-surface.

INSTRUMENT(S): Q Exactive

ORGANISM(S): Homo Sapiens (human)

TISSUE(S): Cell Culture

SUBMITTER: Sachin Singh

LAB HEAD: Jørgen Wesche

PROVIDER: PXD009302 | Pride | 2018-06-06

REPOSITORIES: Pride

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Proximity Labeling by a Recombinant APEX2-FGF1 Fusion Protein Reveals Interaction of FGF1 with the Proteoglycans CD44 and CSPG4.

Zhen Yan Y Haugsten Ellen Margrethe EM Singh Sachin Kumar SK Wesche Jørgen J

Biochemistry 20180613 26

Fibroblast growth factor 1 (FGF1) binds to specific FGF receptors (FGFRs) at the surface of target cells to initiate intracellular signaling. While heparan sulfate proteoglycans (HSPGs) are well-described coreceptors, it is uncertain whether there are additional binding sites for FGF1 at the cell surface. To address this, we devised and tested a method to identify novel binding sites for FGF1 at the cell surface, which may also be applicable for other protein ligands. We constructed an APEX2-FGF ...[more]

PMID: 29812912

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