1qg3 is a 2 chain structure with sequence from Homo sapiens. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
ITB4_HUMAN Defects in ITGB4 are a cause of epidermolysis bullosa letalis with pyloric atresia (EB-PA) [MIM:226730; also known as junctional epidermolysis bullosa with pyloric atresia (PA-JEB) or aplasia cutis congenita with gastrointestinal atresia. EB-PA is an autosomal recessive, frequently lethal, epidermolysis bullosa with variable involvement of skin, nails, mucosa, and with variable effects on the digestive system. It is characterized by mucocutaneous fragility, aplasia cutis congenita, and gastrointestinal atresia, which most commonly affects the pylorus. Pyloric atresia is a primary manifestation rather than a scarring process secondary to epidermolysis bullosa.[1][2][3][4][5][6][7] Defects in ITGB4 are a cause of generalized atrophic benign epidermolysis bullosa (GABEB) [MIM:226650. GABEB is a non-lethal, adult form of junctional epidermolysis bullosa characterized by life-long blistering of the skin, associated with hair and tooth abnormalities.[8]
Function
ITB4_HUMAN Integrin alpha-6/beta-4 is a receptor for laminin. Plays a critical structural role in the hemidesmosome of epithelial cells. Is required for the regulation of keratinocyte polarity and motility.[9][10]
Evolutionary Conservation
Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.
Publication Abstract from PubMed
The integrin alpha6beta4 is an essential component of hemidesmosomes but it also plays a dynamic role in invasive carcinoma cells. The cytoplasmic tail of the beta4 subunit is uniquely large among integrins and includes two pairs of fibronectin type III domains separated by a connecting segment. Here we describe the crystal structure of the first tandem domain pair, a module that is critical for alpha6beta4 function. The structure reveals a novel interdomain interface and candidate protein-binding sites, including a large acidic cleft formed from the surfaces of both domains and a prominent loop that is reminiscent of the RGD integrin-binding loop of fibronectin. This is the first crystal structure of either a hemidesmosome component or an integrin cytoplasmic domain, and it will enable the intracellular functions of alpha6beta4 to be dissected at the atomic level.
Crystal structure of a tandem pair of fibronectin type III domains from the cytoplasmic tail of integrin alpha6beta4.,de Pereda JM, Wiche G, Liddington RC EMBO J. 1999 Aug 2;18(15):4087-95. PMID:10428948[11]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
↑Pulkkinen L, Rouan F, Bruckner-Tuderman L, Wallerstein R, Garzon M, Brown T, Smith L, Carter W, Uitto J. Novel ITGB4 mutations in lethal and nonlethal variants of epidermolysis bullosa with pyloric atresia: missense versus nonsense. Am J Hum Genet. 1998 Nov;63(5):1376-87. PMID:9792864 doi:S0002-9297(07)61568-7
↑Pulkkinen L, Kim DU, Uitto J. Epidermolysis bullosa with pyloric atresia: novel mutations in the beta4 integrin gene (ITGB4). Am J Pathol. 1998 Jan;152(1):157-66. PMID:9422533
↑Pulkkinen L, Bruckner-Tuderman L, August C, Uitto J. Compound heterozygosity for missense (L156P) and nonsense (R554X) mutations in the beta4 integrin gene (ITGB4) underlies mild, nonlethal phenotype of epidermolysis bullosa with pyloric atresia. Am J Pathol. 1998 Apr;152(4):935-41. PMID:9546354
↑Mellerio JE, Pulkkinen L, McMillan JR, Lake BD, Horn HM, Tidman MJ, Harper JI, McGrath JA, Uitto J, Eady RA. Pyloric atresia-junctional epidermolysis bullosa syndrome: mutations in the integrin beta4 gene (ITGB4) in two unrelated patients with mild disease. Br J Dermatol. 1998 Nov;139(5):862-71. PMID:9892956
↑Kambham N, Tanji N, Seigle RL, Markowitz GS, Pulkkinen L, Uitto J, D'Agati VD. Congenital focal segmental glomerulosclerosis associated with beta4 integrin mutation and epidermolysis bullosa. Am J Kidney Dis. 2000 Jul;36(1):190-6. PMID:10873890
↑Nakano A, Pulkkinen L, Murrell D, Rico J, Lucky AW, Garzon M, Stevens CA, Robertson S, Pfendner E, Uitto J. Epidermolysis bullosa with congenital pyloric atresia: novel mutations in the beta 4 integrin gene (ITGB4) and genotype/phenotype correlations. Pediatr Res. 2001 May;49(5):618-26. PMID:11328943
↑Inoue M, Tamai K, Shimizu H, Owaribe K, Nakama T, Hashimoto T, McGrath JA. A homozygous missense mutation in the cytoplasmic tail of beta4 integrin, G931D, that disrupts hemidesmosome assembly and underlies Non-Herlitz junctional epidermolysis bullosa without pyloric atresia? J Invest Dermatol. 2000 May;114(5):1061-4. PMID:10792571 doi:10.1046/j.1523-1747.2000.00960-3.x
↑Koster J, Geerts D, Favre B, Borradori L, Sonnenberg A. Analysis of the interactions between BP180, BP230, plectin and the integrin alpha6beta4 important for hemidesmosome assembly. J Cell Sci. 2003 Jan 15;116(Pt 2):387-99. PMID:12482924
↑Hamill KJ, Hopkinson SB, DeBiase P, Jones JC. BPAG1e maintains keratinocyte polarity through beta4 integrin-mediated modulation of Rac1 and cofilin activities. Mol Biol Cell. 2009 Jun;20(12):2954-62. doi: 10.1091/mbc.E09-01-0051. Epub 2009, Apr 29. PMID:19403692 doi:10.1091/mbc.E09-01-0051
↑de Pereda JM, Wiche G, Liddington RC. Crystal structure of a tandem pair of fibronectin type III domains from the cytoplasmic tail of integrin alpha6beta4. EMBO J. 1999 Aug 2;18(15):4087-95. PMID:10428948 doi:https://dx.doi.org/10.1093/emboj/18.15.4087
