Abstract
Pentraxin 3 (PTX3) and heavy chains (HCs) of inter-α-trypsin inhibitor (IαI) are essential for hyaluronan (HA) organization within the extracellular matrix of the cumulus oophorus, which is critical for in vivo oocyte fertilization and female fertility. In this study, we examined the possibility that these molecules interact and cooperate in this function. We show that HCs and PTX3 colocalize in the cumulus matrix and coimmunoprecipitate from cumulus matrix extracts. Coimmunoprecipitation experiments and solid-phase binding assays performed with purified human IαI and recombinant PTX3 demonstrate that their interaction is direct and not mediated by other matrix components. PTX3 does not bind to IαI subcomponent bikunin and, accordingly, bikunin does not compete for the binding of PTX3 to IαI, indicating that PTX3 interacts with IαI subcomponent HC only. Recombinant PTX3-specific N-terminal region, but not the PTX3-pentraxin C-terminal domain, showed the same ability as full-length protein to bind to HCs and to enable HA organization and matrix formation by Ptx3-/- cumulus cell oocyte complexes cultured in vitro. Furthermore, a monoclonal antibody raised against PTX3 N terminus, which inhibits PTX3/IαI interaction, also prevents recombinant full-length PTX3 from restoring a normal phenotype to in vitro-cultured Ptx3-/- cumuli. These results indicate that PTX3 directly interacts with HCs of IαI and that such interaction is essential for organizing HA in the viscoelastic matrix of cumulus oophorus, highlighting a direct functional link between the two molecules.
| Original language | English |
|---|---|
| Pages (from-to) | 30161-30170 |
| Number of pages | 10 |
| Journal | Journal of Biological Chemistry |
| Volume | 282 |
| Issue number | 41 |
| DOIs | |
| Publication status | Published - Oct 12 2007 |
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ASJC Scopus subject areas
- Biochemistry
Cite this
PTX3 interacts with inter-α-trypsin inhibitor : Implications for hyaluronan organization and cumulus oophorus expansion. / Scarchilli, Laura; Camaioni, Antonella; Bottazzi, Barbara; Negri, Veronica; Doni, Andrea; Deban, Livija; Bastone, Antonio; Salvatori, Giovanni; Mantovani, Alberto; Siracusa, Gregorio; Salustri, Antonietta.
In: Journal of Biological Chemistry, Vol. 282, No. 41, 12.10.2007, p. 30161-30170.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - PTX3 interacts with inter-α-trypsin inhibitor
T2 - Implications for hyaluronan organization and cumulus oophorus expansion
AU - Scarchilli, Laura
AU - Camaioni, Antonella
AU - Bottazzi, Barbara
AU - Negri, Veronica
AU - Doni, Andrea
AU - Deban, Livija
AU - Bastone, Antonio
AU - Salvatori, Giovanni
AU - Mantovani, Alberto
AU - Siracusa, Gregorio
AU - Salustri, Antonietta
PY - 2007/10/12
Y1 - 2007/10/12
N2 - Pentraxin 3 (PTX3) and heavy chains (HCs) of inter-α-trypsin inhibitor (IαI) are essential for hyaluronan (HA) organization within the extracellular matrix of the cumulus oophorus, which is critical for in vivo oocyte fertilization and female fertility. In this study, we examined the possibility that these molecules interact and cooperate in this function. We show that HCs and PTX3 colocalize in the cumulus matrix and coimmunoprecipitate from cumulus matrix extracts. Coimmunoprecipitation experiments and solid-phase binding assays performed with purified human IαI and recombinant PTX3 demonstrate that their interaction is direct and not mediated by other matrix components. PTX3 does not bind to IαI subcomponent bikunin and, accordingly, bikunin does not compete for the binding of PTX3 to IαI, indicating that PTX3 interacts with IαI subcomponent HC only. Recombinant PTX3-specific N-terminal region, but not the PTX3-pentraxin C-terminal domain, showed the same ability as full-length protein to bind to HCs and to enable HA organization and matrix formation by Ptx3-/- cumulus cell oocyte complexes cultured in vitro. Furthermore, a monoclonal antibody raised against PTX3 N terminus, which inhibits PTX3/IαI interaction, also prevents recombinant full-length PTX3 from restoring a normal phenotype to in vitro-cultured Ptx3-/- cumuli. These results indicate that PTX3 directly interacts with HCs of IαI and that such interaction is essential for organizing HA in the viscoelastic matrix of cumulus oophorus, highlighting a direct functional link between the two molecules.
AB - Pentraxin 3 (PTX3) and heavy chains (HCs) of inter-α-trypsin inhibitor (IαI) are essential for hyaluronan (HA) organization within the extracellular matrix of the cumulus oophorus, which is critical for in vivo oocyte fertilization and female fertility. In this study, we examined the possibility that these molecules interact and cooperate in this function. We show that HCs and PTX3 colocalize in the cumulus matrix and coimmunoprecipitate from cumulus matrix extracts. Coimmunoprecipitation experiments and solid-phase binding assays performed with purified human IαI and recombinant PTX3 demonstrate that their interaction is direct and not mediated by other matrix components. PTX3 does not bind to IαI subcomponent bikunin and, accordingly, bikunin does not compete for the binding of PTX3 to IαI, indicating that PTX3 interacts with IαI subcomponent HC only. Recombinant PTX3-specific N-terminal region, but not the PTX3-pentraxin C-terminal domain, showed the same ability as full-length protein to bind to HCs and to enable HA organization and matrix formation by Ptx3-/- cumulus cell oocyte complexes cultured in vitro. Furthermore, a monoclonal antibody raised against PTX3 N terminus, which inhibits PTX3/IαI interaction, also prevents recombinant full-length PTX3 from restoring a normal phenotype to in vitro-cultured Ptx3-/- cumuli. These results indicate that PTX3 directly interacts with HCs of IαI and that such interaction is essential for organizing HA in the viscoelastic matrix of cumulus oophorus, highlighting a direct functional link between the two molecules.
UR - http://www.scopus.com/inward/record.url?scp=35648969643&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=35648969643&partnerID=8YFLogxK
U2 - 10.1074/jbc.M703738200
DO - 10.1074/jbc.M703738200
M3 - Article
C2 - 17675295
AN - SCOPUS:35648969643
VL - 282
SP - 30161
EP - 30170
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
SN - 0021-9258
IS - 41
ER -