| Structural highlights
Disease
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]
Publication Abstract from PubMed
Mechanical stability of epithelia requires firm attachment to the basement membrane via hemidesmosomes. Dysfunction of hemidesmosomal proteins causes severe skin-blistering diseases. Two plakins, plectin and BP230 (BPAG1e), link the integrin alpha6beta4 to intermediate filaments in epidermal hemidesmosomes. Here, we show that a linear sequence within the isoform-specific N-terminal region of BP230 binds to the third and fourth FnIII domains of beta4. The crystal structure of the complex and mutagenesis analysis revealed that BP230 binds between the two domains of beta4. BP230 induces closing of the two FnIII domains that are locked in place by an interdomain ionic clasp required for binding. Disruption of BP230-beta4 binding prevents recruitment of BP230 to hemidesmosomes in human keratinocytes, revealing a key role of this interaction for hemidesmosome assembly. Phosphomimetic substitutions in beta4 and BP230 destabilize the complex. Thus, our study provides insights into the architecture of hemidesmosomes and potential mechanisms of regulation.
Integrin alpha6beta4 Recognition of a Linear Motif of Bullous Pemphigoid Antigen BP230 Controls Its Recruitment to Hemidesmosomes.,Manso JA, Gomez-Hernandez M, Carabias A, Alonso-Garcia N, Garcia-Rubio I, Kreft M, Sonnenberg A, de Pereda JM Structure. 2019 Apr 4. pii: S0969-2126(19)30094-2. doi:, 10.1016/j.str.2019.03.016. PMID:31006587[11]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ 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
- ↑ Ashton GH, Sorelli P, Mellerio JE, Keane FM, Eady RA, McGrath JA. Alpha 6 beta 4 integrin abnormalities in junctional epidermolysis bullosa with pyloric atresia. Br J Dermatol. 2001 Feb;144(2):408-14. PMID:11251584
- ↑ 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
- ↑ Manso JA, Gomez-Hernandez M, Carabias A, Alonso-Garcia N, Garcia-Rubio I, Kreft M, Sonnenberg A, de Pereda JM. Integrin alpha6beta4 Recognition of a Linear Motif of Bullous Pemphigoid Antigen BP230 Controls Its Recruitment to Hemidesmosomes. Structure. 2019 Apr 4. pii: S0969-2126(19)30094-2. doi:, 10.1016/j.str.2019.03.016. PMID:31006587 doi:https://dx.doi.org/10.1016/j.str.2019.03.016
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