Characterization of the molecular interaction between tropoelastin and DANCE/fibulin-5.
Fibulin-5 is believed to play an important role in the elastic fiber formation. The present experiments were carried out to characterize the molecular interaction between fibulin-5 and tropoelastin. Our data showed that the divalent cations of Ca(2+), Ba(2+) and Mg(2+) significantly enhanced the binding of fibulin-5 to tropoelastin. In addition, N-linked glycosylation of fibulin-5 does not require for the binding to tropoelastin. To address the fibulin-5 binding site on tropoelastin constructs containing, exons 2-15 and exons 16-36, of tropoelastin were used. Fibulin-5 binding was significantly reduced to either fragment and also to a mixture of the two fragments. These results suggested that the whole molecule of tropoelastin was required for the interaction with fibulin-5. In co-immunoprecipitation experiments, tropoelastin binding to fibulin-5 was enhanced by an increase of temperature and sodium chloride concentration, conditions that enhance the coacervation of tropoelastin. The binding of tropoelastin fragments to fibulin-5 was directly proportional to their propensity to coacervate. Furthermore, the addition of fibulin-5 to tropoelastin facilitated coacervation. Taken together, the present study shows that fibulin-5 enhances elastic fiber formation in part by improving the self-association properties of tropoelastin.
Wachi
Hiroshi
H
Department of Clinical Chemistry, Hoshi University School of Pharmacy and Pharmaceutical Sciences, 2-4-41 Ebara, Shinagawa-ku, Tokyo 142-8501, Japan. wchrs_1107@hoshi.ac.jp
Nonaka
Risa
R
Sato
Fumiaki
F
Shibata-Sato
Kayoko
K
Ishida
Marie
M
Iketani
Saori
S
Maeda
Iori
I
Okamoto
Koji
K
Urban
Zsolt
Z
Onoue
Satoshi
S
Seyama
Yoshiyuki
Y
D000818:Animals; D001665:Binding Sites; D002417:Cattle; D016326:Extracellular Matrix Proteins / Q000737:chemistry* / Q000378:metabolism; D006031:Glycosylation; D006801:Humans; D011485:Protein Binding; D011499:Protein Processing, Post-Translational; D017434:Protein Structure, Tertiary; D014333:Tropoelastin / Q000737:chemistry* / Q000378:metabolism
D016326:Extracellular Matrix Proteins; C492373:FBLN5 protein, human; D014333:Tropoelastin