Tropoelastin aggregate Tropoelastin forms aggregate globules Authored: Jupe, S, 2012-04-30 Edited: Jupe, S, 2012-11-12 Pubmed15172035 Pubmed16192266 Pubmed16906757 Pubmed21081222 Reactome Database ID Release 432161293 Reactome, http://www.reactome.org ReactomeREACT_150175 Reviewed: Muiznieks, Lisa, 2012-11-02 The core protein representing ~90% of the mass of elastic fibres is elastin, a highly insoluble protein. It is secreted as soluble protein monomers referred to as tropoelastin, which have alternating hydrophobic and cross linking domains. The self-assembly of tropoelastin into a fibrillar elastin matrix is a multi step process. The first step is the self-association of secreted monomers via hydrophobic domains, in a process known as coacervation. This process concentrates monomers and may align residues in the correct register for subsequent cross linking (Yeo et al. 2011). Under physiological conditions the ~15 nm monomers phase-separate and coalesce into spherical packages 2-6 micrometers in diameter (Clarke et al. 2006, Kozel et al. 2004). This process is represented here by the association of an arbitrary 10 tropoelastin monomers. While they grow, coacervate packages are tethered to the cell surface. The binding interactions between tropoelastin and the cell surface are not fully understood but possible partners include integrins and glycosaminoglycans (Broekelmann et al. 2005). Extracellular fibrillin microfibrils act as a scaffold for the deposition of tropoelastin globules as part of elastic fibre formation (Kozel et al. 2004). has a Stoichiometric coefficient of 10