Elastin is a protein in connective tissue that is elastic and allows many tissues in the body to resume their shape after stretching or contracting. Elastin helps skin to return to its original position when it is poked or pinched. Elastin is also an important load-bearing tissue in the bodies of vertebrates and used in places where mechanical energy is required to be stored. In humans, elastin is encoded by the ELN gene.
This gene encodes a protein that is one of the two components of elastic fibers. The encoded protein is rich in hydrophobic amino acids such as glycine and proline, which form mobile hydrophobic regions bounded by crosslinks between lysine residues. Multiple transcript variants encoding different isoforms have been found for this gene. The other name for elastin is tropoelastin. The characterization of disorder is consistent with an entropy-driven mechanism of elastic recoil. It is concluded that conformational disorder is a constitutive feature of elastin structure and function.
Clinical significance 
Deletions and mutations in this gene are associated with supravalvular aortic stenosis (SVAS) and autosomal dominant cutis laxa. Other associated defects in elastin include Marfan's Syndrome and emphysema caused by α1-antitrypsin deficiency.
Elastic fiber is composed of the protein fibrillin and elastin made of simple amino acids such as glycine, valine, alanine, and proline. The total elastin ranges from 58 to 75% of the weight of the dry defatted artery in normal canine arteries. Comparison between fresh and digested tissues shows that, at 35% strain, a minimum of 48% of the arterial load is carried by elastin, and a minimum of 43% of the change in stiffness of arterial tissue is due to the change in elastin stiffness. Elastin is made by linking many soluble tropoelastin protein molecules, in a reaction catalyzed by lysyl oxidase, to make a massive insoluble, durable cross-linked array. The amino acid responsible for these cross-links is lysine. Tropoelastin is a specialized protein with a molecular weight of 64 to 66 kDa, and an irregular or random coil conformation made up of 830 amino acids.
Tissue distribution 
Elastin serves an important function in arteries as a medium for pressure wave propagation to help blood flow and is particularly abundant in large elastic blood vessels such as the aorta. Elastin is also very important in the lungs, elastic ligaments, the skin, and the bladder, elastic cartilage. It is present in all vertebrates above the jawless fish.
See also 
- Curran ME, Atkinson DL, Ewart AK, Morris CA, Leppert MF, Keating MT (April 1993). "The elastin gene is disrupted by a translocation associated with supravalvular aortic stenosis". Cell 73 (1): 159–68. doi:10.1016/0092-8674(93)90168-P. PMID 8096434.
- "Entrez Gene: elastin".
- "Elastin (ELN)". Retrieved 31 October 2011.
- Lisa D Muiznieks, Anthony S Weiss and Fred W Keeley (2010). "Structural disorder and dynamics of elastin.". Biochem Cell Biol 88 (2): 239–50. doi:10.1139/o09-161. PMID 20453927.
- Kielty CM, Sherratt MJ, Shuttleworth CA (July 2002). "Elastic fibres". J. Cell. Sci. 115 (Pt 14): 2817–28. PMID 12082143.
- Grace M. Fischer M.D. Josep G. Llaurado M.D. (October 1966). "Collagen and Elastin Content in Canine Arteries Selected from Functionally Different Vascular Beds". Circulation Research 19 (2): 394–399. PMID 5914851.
- Lammers SR, Kao PH, Qi HJ, Hunter K, Lanning C, Albietz J, Hofmeister S, Mecham R, Stenmark KR, Shandas R. (July 2008). "Changes in the structure-function relationship of elastin and its impact on the proximal pulmonary arterial mechanics of hypertensive calves". Am J Physiol Heart Circ Physiol. 295 (4): H1451–9. doi:10.1152/ajpheart.00127.2008. PMID 18660454.
- Sage EH, Gray WR (1977). "Evolution of elastin structure". Adv. Exp. Med. Biol. 79: 291–312. PMID 868643.
Further reading 
- Jan SL, Chan SC, Fu YC, Lin SJ (2009). "Elastin gene study of infants with isolated congenital ductus arteriosus aneurysm.". Acta Cardiol 64 (3): 363–9. PMID 19593948.
- Keeley FW, Bellingham CM, Woodhouse KA (2002). "Elastin as a self-organizing biomaterial: use of recombinantly expressed human elastin polypeptides as a model for investigations of structure and self-assembly of elastin". Philos. Trans. R. Soc. Lond., B, Biol. Sci. 357 (1418): 185–9. doi:10.1098/rstb.2001.1027. PMC 1692930. PMID 11911775.
- Choudhury R, McGovern A, Ridley C et al. (2009). "Differential regulation of elastic fiber formation by fibulin-4 and -5". J. Biol. Chem. 284 (36): 24553–67. doi:10.1074/jbc.M109.019364. PMC 2782046. PMID 19570982.
- Hubmacher D, Cirulis JT, Miao M et al. (2010). "Functional consequences of homocysteinylation of the elastic fiber proteins fibrillin-1 and tropoelastin". J. Biol. Chem. 285 (2): 1188–98. doi:10.1074/jbc.M109.021246. PMC 2801247. PMID 19889633.
- Coolen NA, Schouten KC, Middelkoop E, Ulrich MM (2010). "Comparison between human fetal and adult skin". Arch. Dermatol. Res. 302 (1): 47–55. doi:10.1007/s00403-009-0989-8. PMC 2799629. PMID 19701759.
- McGeachie M, Ramoni RL, Mychaleckyj JC et al. (2009). "Integrative predictive model of coronary artery calcification in atherosclerosis". Circulation 120 (24): 2448–54. doi:10.1161/CIRCULATIONAHA.109.865501. PMC 2810344. PMID 19948975.
- Yoshida T, Kato K, Yokoi K et al. (2009). "Association of genetic variants with chronic kidney disease in individuals with different lipid profiles". Int. J. Mol. Med. 24 (2): 233–46. PMID 19578796.
- Akima T, Nakanishi K, Suzuki K et al. (2009). "Soluble elastin decreases in the progress of atheroma formation in human aorta". Circ. J. 73 (11): 2154–62. PMID 19755752.
- Chen Q, Zhang T, Roshetsky JF et al. (2009). "Fibulin-4 regulates expression of the tropoelastin gene and consequent elastic-fibre formation by human fibroblasts". Biochem. J. 423 (1): 79–89. doi:10.1042/BJ20090993. PMC 3024593. PMID 19627254.
- Tintar D, Samouillan V, Dandurand J et al. (2009). "Human tropoelastin sequence: dynamics of polypeptide coded by exon 6 in solution". Biopolymers 91 (11): 943–52. doi:10.1002/bip.21282. PMID 19603496.
- Dyksterhuis LB, Weiss AS (2010). "Homology models for domains 21-23 of human tropoelastin shed light on lysine crosslinking". Biochem. Biophys. Res. Commun. 396 (4): 870–3. doi:10.1016/j.bbrc.2010.05.013. PMID 20457133.
- Romero R, Velez Edwards DR, Kusanovic JP et al. (2010). "Identification of fetal and maternal single nucleotide polymorphisms in candidate genes that predispose to spontaneous preterm labor with intact membranes". Am. J. Obstet. Gynecol. 202 (5): 431.e1–34. doi:10.1016/j.ajog.2010.03.026. PMID 20452482.
- Fan BJ, Figuieredo Sena DR, Pasquale LR et al. (2009). "Lack of Association of Polymorphisms in Elastin With Pseudoexfoliation Syndrome and Glaucoma". Journal of glaucoma 19 (7): 432–436. doi:10.1097/IJG.0b013e3181c4b0fe. PMID 20051886.
- Bertram C, Hass R (2009). "Cellular senescence of human mammary epithelial cells (HMEC) is associated with an altered MMP-7/HB-EGF signaling and increased formation of elastin-like structures". Mech. Ageing Dev. 130 (10): 657–69. doi:10.1016/j.mad.2009.08.001. PMID 19682489.
- Roberts KE, Kawut SM, Krowka MJ et al. (2010). "Genetic risk factors for hepatopulmonary syndrome in patients with advanced liver disease". Gastroenterology 139 (1): 130–9.e24. doi:10.1053/j.gastro.2010.03.044. PMC 2908261. PMID 20346360.
- Rosenbloom J (1984). "Elastin: relation of protein and gene structure to disease". Lab. Invest. 51 (6): 605–23. PMID 6150137.
- Bax DV, Rodgers UR, Bilek MM, Weiss AS (2009). "Cell adhesion to tropoelastin is mediated via the C-terminal GRKRK motif and integrin alphaVbeta3". J. Biol. Chem. 284 (42): 28616–23. doi:10.1074/jbc.M109.017525. PMC 2781405. PMID 19617625.
- Rodriguez-Revenga L, Iranzo P, Badenas C et al. (2004). "A novel elastin gene mutation resulting in an autosomal dominant form of cutis laxa". Arch Dermatol 140 (9): 1135–9. doi:10.1001/archderm.140.9.1135. PMID 15381555.
- Micale L, Turturo MG, Fusco C et al. (2010). "Identification and characterization of seven novel mutations of elastin gene in a cohort of patients affected by supravalvular aortic stenosis". Eur. J. Hum. Genet. 18 (3): 317–23. doi:10.1038/ejhg.2009.181. PMC 2987220. PMID 19844261.
- Tzaphlidou M (2004). "The role of collagen and elastin in aged skin: an image processing approach". Micron 35 (3): 173–7. doi:10.1016/j.micron.2003.11.003. PMID 15036271.
- Elastin at the US National Library of Medicine Medical Subject Headings (MeSH)
- BU Histology Learning System: 21402loa
- GeneReviews/NIH/NCBI/UW entry on Williams or Williams-Beuren Syndrome
- The Elastin Protein