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Publications (2)6.45 Total impact

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    ABSTRACT: Recent evidences suggest that plastin/fimbrin is more than a simple actin cross-linking molecule. In this context and based on the fact that other members of the same family interact with transmembrane proteins, such as integrins, we have investigated a possible interaction between L-plastin and integrins. By combining coimmunoprecipitation of endogenous proteins and in vitro techniques based on solid phase and solution assays, we demonstrate that L-plastin is an additional binding partner for the beta-chain of integrin and confirmed that both proteins display some colocalization. We then show that L-plastin binds to the cytoplasmic domain of beta1 integrin and to beta1 and beta2 peptides. Using recombinant L-plastin domains, we demonstrate that the integrin-binding sites are not located in NH(2) terminal part of L-plastin but rather in the two actin-binding domains. Using pull-down, cross-linking experiments, and enzyme-linked immunosorbent assay, we show that the L-plastin/integrin complex is regulated by mu-calpain cleavage and is not directly dissociated by calcium. Indeed, despite the ability of calpain to cleave both proteins, only the cleavage of beta integrin hindered the formation of the L-plastin/integrin complex. We discuss these results in the light of the three-dimensional structure of the actin-binding domains of L-plastin.
    Cytoskeleton 02/2010; 67(5):286-96. · 2.87 Impact Factor
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    ABSTRACT: Gelsolin is an actin-binding protein that is regulated by the occupancy of multiple calcium-binding sites. We have studied calcium induced conformational changes in the G1-2 and G1-3 sub-domains, and report the binding affinities for the three type II sites. A new probe for G3 has been produced and a K(d) of 5 microM has been measured for calcium in the context of G1-3. The two halves of gelsolin, G1-3 and G4-6 bind weakly with or without calcium, suggesting that once separated by apoptotic proteolysis, G1-3 and G4-6 remain apart allowing G1-3 to sever actin in a calcium free manner.
    FEBS Letters 03/2007; 581(4):681-6. · 3.58 Impact Factor