The EMILIN protein family

The EMILINs are a new family of glycoproteins of the extracellular matrix. The prototype of this family is the chicken EMILIN that was originally iden tified in extracts of aortas; it was then found to be widely distributed in several tissues associated with elastin and localized at the interface bet ween amorphous elastin and microfibrils. Based on peptide sequences, chicke n and human cDNAs coding for EMILIN were isolated by RT/PCR by screening ki dney and heart cDNA libraries. By using a C-terminal fragment of human EMIL IN-1 as a bait in the yeast two-hybrid system, a second family member, EMIL IN-2, has also been isolated. EMILINs are characterized by a C-terminal gC1 q globular domain, a short collagenous sequence, a long coiled-coil region and a new cysteine-rich N-terminal domain that can be considered a hallmark of the family being present also in multimerin. The gene for EMILIN-1 was mapped on chromosome 2p23 overlapping with the promoter region of the ketoh exokinase gene. The gC1q domain of EMILIN-1 can form relatively stable and compact homotrimers and this association is then followed by a multimeric a ssembly of disulfide-bonded protomers. Recombinant EMILIN-1 purified from t he supernatant of 293 cells represents a very efficient ligand for cell adh esion of several cell types. (C) 2000 Published by Elsevier Science B.V./In ternational Society of Matrix Biology. All rights reserved.