Domains 16 and 17 of tropoelastin in elastic fibre formation.
Naturally occurring mutations are useful in identifying domains that are important for protein function. We studied a mutation in the elastin gene, 800-3G>C, a common disease allele for SVAS (supravalvular aortic stenosis). We showed in primary skin fibroblasts from two different SVAS families that this mutation causes skipping of exons 16-17 and results in a stable mRNA. Tropoelastin lacking domains 16-17 (Delta16-17) was synthesized efficiently and secreted by transfected retinal pigment epithelium cells, but showed the deficient deposition into the extracellular matrix compared with normal as demonstrated by immunofluorescent staining and desmosine assays. Solid-phase binding assays indicated normal molecular interaction of Delta16-17 with fibrillin-1 and fibulin-5. However, self-association of Delta16-17 was diminished as shown by an elevated coacervation temperature. Moreover, negative staining electron microscopy confirmed that Delta16-17 was deficient in forming fibrillar polymers. Domain 16 has high homology with domain 30, which can form a beta-sheet structure facilitating fibre formation. Taken together, we conclude that domains 16-17 are important for self-association of tropoelastin and elastic fibre formation. This study is the first to discover that domains of elastin play an essential role in elastic fibre formation by facilitating homotypic interactions.
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. wachi@hoshi.ac.jp
Sato
Fumiaki
F
Nakazawa
Junji
J
Nonaka
Risa
R
Szabo
Zoltan
Z
Urban
Zsolt
Z
Yasunaga
Takuo
T
Maeda
Iori
I
Okamoto
Koji
K
Starcher
Barry C
BC
Li
Dean Y
DY
Mecham
Robert P
RP
Seyama
Yoshiyuki
Y
D000595:Amino Acid Sequence; D021921:Aortic Stenosis, Supravalvular / Q000235:genetics / Q000378:metabolism; D004547:Elastic Tissue / Q000502:physiology*; D016326:Extracellular Matrix Proteins / Q000378:metabolism; D005347:Fibroblasts / Q000378:metabolism; D006801:Humans; D020894:Microfibrils / Q000502:physiology; D008969:Molecular Sequence Data; D009154:Mutation; D017434:Protein Structure, Tertiary; D012333:RNA, Messenger / Q000378:metabolism; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism; D013696:Temperature; D014162:Transfection; D014333:Tropoelastin / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism
D016326:Extracellular Matrix Proteins; C492373:FBLN5 protein, human; D012333:RNA, Messenger; D011994:Recombinant Proteins; D014333:Tropoelastin