DEFA4

{{Short description|Protein-coding gene in the species Homo sapiens}} {{Infobox_gene}}

'''Defensin, alpha 4''' ('''DEFA4'''), also known as '''neutrophil defensin 4''' or '''HNP4''', is a human defensin peptide that is encoded by the ''DEFA4'' gene.<ref name="entrez">{{Cite web| title = Entrez Gene: DEFA4; defensin, alpha 4, corticostatin (''Homo sapiens'') | url = https://www.ncbi.nlm.nih.gov/gene?Db=gene&Cmd=ShowDetailView&TermToSearch=1669}}</ref><ref name="pmid15317502">{{cite journal | vauthors = Wu Z, Ericksen B, Tucker K, Lubkowski J, Lu W | title = Synthesis and characterization of human alpha-defensins 4-6 | journal = The Journal of Peptide Research | volume = 64 | issue = 3 | pages = 118–25 | date = September 2004 | pmid = 15317502 | doi = 10.1111/j.1399-3011.2004.00179.x }}</ref> HNP4 is expressed in the granules of the neutrophil where it defends the host against bacteria<ref name="pmid15616305">{{cite journal | vauthors = Ericksen B, Wu Z, Lu W, Lehrer RI | title = Antibacterial activity and specificity of the six human {alpha}-defensins | journal = Antimicrobial Agents and Chemotherapy | volume = 49 | issue = 1 | pages = 269–75 | date = January 2005 | pmid = 15616305 | pmc = 538877 | doi = 10.1128/AAC.49.1.269-275.2005 }}</ref> and viruses.<ref name="pmid15620707">{{cite journal | vauthors = Wu Z, Cocchi F, Gentles D, Ericksen B, Lubkowski J, Devico A, Lehrer RI, Lu W | display-authors = 6 | title = Human neutrophil alpha-defensin 4 inhibits HIV-1 infection in vitro | journal = FEBS Letters | volume = 579 | issue = 1 | pages = 162–6 | date = January 2005 | pmid = 15620707 | doi = 10.1016/j.febslet.2004.11.062 | bibcode = 2005FEBSL.579..162W | s2cid = 84062495 | doi-access = free }}</ref>

== Function == Defensins are a peptide family of cytotoxic microbicides involved in innate immunity.<ref name="pmid2997278">{{cite journal | vauthors = Ganz T, Selsted ME, Szklarek D, Harwig SS, Daher K, Bainton DF, Lehrer RI | title = Defensins. Natural peptide antibiotics of human neutrophils | journal = The Journal of Clinical Investigation | volume = 76 | issue = 4 | pages = 1427–35 | date = October 1985 | pmid = 2997278 | pmc = 424093 | doi = 10.1172/JCI112120 }}</ref> Members of the defensin family are distinguished by a conserved six-cysteine motif. Several human alpha defensin genes including HNP4 are clustered on chromosome 8. ''DEFA4'' differs from other defensin genes by an extra 83-base segment that is apparently the result of a recent duplication within the coding region. HNP4 inhibits corticotropin-stimulated corticosterone production.<ref name="entrez"/>

== References == {{Reflist}}

== Further reading == {{Refbegin| 2}} * {{cite journal | vauthors = Szyk A, Wu Z, Tucker K, Yang D, Lu W, Lubkowski J | title = Crystal structures of human alpha-defensins HNP4, HD5, and HD6 | journal = Protein Science | volume = 15 | issue = 12 | pages = 2749–60 | date = December 2006 | pmid = 17088326 | pmc = 2242434 | doi = 10.1110/ps.062336606 }} * {{cite journal | vauthors = Mallow EB, Harris A, Salzman N, Russell JP, DeBerardinis RJ, Ruchelli E, Bevins CL | title = Human enteric defensins. Gene structure and developmental expression | journal = The Journal of Biological Chemistry | volume = 271 | issue = 8 | pages = 4038–45 | date = February 1996 | pmid = 8626737 | doi = 10.1074/jbc.271.8.4038 | doi-access = free }} * {{cite journal | vauthors = Bevins CL, Jones DE, Dutra A, Schaffzin J, Muenke M | title = Human enteric defensin genes: chromosomal map position and a model for possible evolutionary relationships | journal = Genomics | volume = 31 | issue = 1 | pages = 95–106 | date = January 1996 | pmid = 8808285 | doi = 10.1006/geno.1996.0014 }} * {{cite journal | vauthors = Gabay JE, Scott RW, Campanelli D, Griffith J, Wilde C, Marra MN, Seeger M, Nathan CF | display-authors = 6 | title = Antibiotic proteins of human polymorphonuclear leukocytes | journal = Proceedings of the National Academy of Sciences of the United States of America | volume = 86 | issue = 14 | pages = 5610–4 | date = July 1989 | pmid = 2501794 | pmc = 297672 | doi = 10.1073/pnas.86.14.5610 | bibcode = 1989PNAS...86.5610G | doi-access = free }} * {{cite journal | vauthors = Davila S, Froeling FE, Tan A, Bonnard C, Boland GJ, Snippe H, Hibberd ML, Seielstad M | display-authors = 6 | title = New genetic associations detected in a host response study to hepatitis B vaccine | journal = Genes and Immunity | volume = 11 | issue = 3 | pages = 232–8 | date = April 2010 | pmid = 20237496 | doi = 10.1038/gene.2010.1 | doi-access = free }} * {{cite journal | vauthors = Kim E, Lee JE, Namkung JH, Kim PS, Kim S, Shin ES, Cho EY, Yang JM | display-authors = 6 | title = Single nucleotide polymorphisms and the haplotype in the DEFB1 gene are associated with atopic dermatitis in a Korean population | journal = Journal of Dermatological Science | volume = 54 | issue = 1 | pages = 25–30 | date = April 2009 | pmid = 19135873 | doi = 10.1016/j.jdermsci.2008.12.005 }} * {{cite journal | vauthors = Milanese M, Segat L, Arraes LC, Garzino-Demo A, Crovella S | title = Copy number variation of defensin genes and HIV infection in Brazilian children | journal = Journal of Acquired Immune Deficiency Syndromes | volume = 50 | issue = 3 | pages = 331–3 | date = March 2009 | pmid = 19194307 | doi = 10.1097/QAI.0b013e3181945f39 | s2cid = 33161105 | doi-access = free }} * {{cite journal | vauthors = Palfree RG, Sadro LC, Solomon S | title = The gene encoding the human corticostatin HP-4 precursor contains a recent 86-base duplication and is located on chromosome 8 | journal = Molecular Endocrinology | volume = 7 | issue = 2 | pages = 199–205 | date = February 1993 | doi = 10.1210/mend.7.2.8469233 | pmid = 8469233 | s2cid = 13126788 | doi-access = free }} * {{cite journal | vauthors = Furci L, Sironi F, Tolazzi M, Vassena L, Lusso P | title = Alpha-defensins block the early steps of HIV-1 infection: interference with the binding of gp120 to CD4 | journal = Blood | volume = 109 | issue = 7 | pages = 2928–35 | date = April 2007 | pmid = 17132727 | doi = 10.1182/blood-2006-05-024489 | doi-access = free }} * {{cite journal | vauthors = Wilde CG, Griffith JE, Marra MN, Snable JL, Scott RW | title = Purification and characterization of human neutrophil peptide 4, a novel member of the defensin family | journal = The Journal of Biological Chemistry | volume = 264 | issue = 19 | pages = 11200–3 | date = July 1989 | pmid = 2500436 | doi = 10.1016/S0021-9258(18)60449-1 | doi-access = free }} * {{cite journal | vauthors = Singh A, Bateman A, Zhu QZ, Shimasaki S, Esch F, Solomon S | title = Structure of a novel human granulocyte peptide with anti-ACTH activity | journal = Biochemical and Biophysical Research Communications | volume = 155 | issue = 1 | pages = 524–9 | date = August 1988 | pmid = 2843187 | doi = 10.1016/S0006-291X(88)81118-5 | bibcode = 1988BBRC..155..524S }} * {{cite journal | vauthors = Konishi K, Gibson KF, Lindell KO, Richards TJ, Zhang Y, Dhir R, Bisceglia M, Gilbert S, Yousem SA, Song JW, Kim DS, Kaminski N | display-authors = 6 | title = Gene expression profiles of acute exacerbations of idiopathic pulmonary fibrosis | journal = American Journal of Respiratory and Critical Care Medicine | volume = 180 | issue = 2 | pages = 167–75 | date = July 2009 | pmid = 19363140 | pmc = 2714820 | doi = 10.1164/rccm.200810-1596OC }} * {{cite journal | vauthors = Emonts M, Vermont CL, Houwing-Duistermaat JJ, Haralambous E, Gaast-de Jongh CE, Hazelzet JA, Faust SN, Betts H, Hermans PW, Levin M, de Groot R | display-authors = 6 | title = Polymorphisms in PARP, IL1B, IL4, IL10, C1INH, DEFB1, and DEFA4 in meningococcal disease in three populations | journal = Shock | volume = 34 | issue = 1 | pages = 17–22 | date = July 2010 | pmid = 20016407 | doi = 10.1097/SHK.0b013e3181ce2c7d | s2cid = 21743951 | doi-access = free }} {{Refend}}

{{DEFAULTSORT:Defa4}} Category:Defensins