elastin; tropoelastin (ELN)

Function

• elastic protein in connective tissue
• allows many tissues in the body to resume their shape after stretching or contracting
• helps skin to return to its original position when displaced
• role in load-bearing tissue where mechanical energy is stored (tendons)
• forms a ternary complex with BGN & MFAP2
• interacts with MFAP2 via divalent cations (Ca+2 > Mg+2 > Mn+2) dose-dependent & saturatable

Structure

• primarily composed of Gly, Val, Ala, & Pro
• made by linking many soluble tropoelastins, in a reaction catalyzed by lysyl oxidase, to make a massive insoluble, durable cross-linked array
• cross-linking is via Lys
• most abundant cross-links in mature elastin fibers are lysinonorleucine, allysine aldol, desmosine, & isodesmosine
• hydroxylation on proline residues within the sequence motif, GXPG

Compartment

extracellular matrix

Alternative splicing

named isoforms=13

Expression

• arteries, especially large elastic blood vessels (aorta)
• lungs, elastic ligaments, skin, bladder, & elastic cartilage

Pathology

• defects in ELN are the cause of
  • cutis laxa, autosomal dominant, type 1
  • supravalvular aortic stenosis
• haploinsufficiency of ELN may be the cause of certain cardiovascular & musculoskeletal abnormalities observed in Williams-Beuren syndrome

Genetics

• the elastin gene is located in the Williams-Beuren syndrome critical region

More general terms

• matrix protein

More specific terms

• tropoelastin

Additional terms

• elastase
• elastin receptor (ELNR1)

Component of

• elastic fiber (yellow fiber)

Database

• Entrez gene: http://www.ncbi.nlm.nih.gov/sites/entrez?db=gene&cmd=Retrieve&dopt=Graphics&list_uids=2006
• Kegg: http://www.genome.jp/dbget-bin/www_bget?hsa:2006
• OMIM: https://mirror.omim.org/entry/123700
• OMIM: https://mirror.omim.org/entry/130160
• OMIM: https://mirror.omim.org/entry/185500
• UniProt: http://www.uniprot.org/uniprot/P15502.html