Klasa 2-DQ afa 1 glavnog kompleksa histokompatibilnosti , znana i kao HLA -DQA1gen na kratkom (p) kraku hromosoma 6 , sekvenca 6p21.3, znan i po oznaci lokusa koji sadrži ovaj gen.[ 5] Protein kodiran ovim genom jedan je od dva proteina koji su potrebni za formiranje DQ heterodimernog , receptora ćelijske površine bitne za funkciju imunskog sistema .
Dužina polipeptidnog lanca je 128 aminokiselina , а molekulska težina 13.906 Da .[ 6]
10 20 30 40 50 MSGRGKQGGK ARAKAKTRSS RAGLQFPVGR VHRLLRKGNY AERVGAGAPV YLAAVLEYLT AEILELAGNA ARDNKKTRII PRHLQLAIRN DEELNKLLGK VTIAQGGVLP NIQAVLLPKK TESHHKAK
Alfa lanac sadrži pet egzona . Egzon 1 kodira vodeći peptid , egzoni 2 i 3 kodiraju dva vanćelijska proteinska domena , egzon 4 kodira transmembranski domen i citoplazmatski rep . Unutar molekula DQ i alfa-lanac i beta-lanac sadrže polimorfizme , specificirajući posebnosti vezivanja peptida , što rezultira u četiri različite molekule. Tipizacija ovih polimorfizama rutinski se vrši za transplantaciju koštane srži .[ 5] [ 7]
Četiri su uobičajena alela DQA1: DQA1 *0101, *0102, *0103, *0104. Ovi aleli se uvijek nalaze u haplotipovima sa HLA-DQB1*05 (DQ5 ) i HLA-DQB1*06 (DQ6 ). DQ1 je serotip, rijedak među serotipovima za ljudske antigene klase II, po tome što antitijela na DQ1 reagiraju na alfa-lanac HLA DQ, ovih proizvoda gena alela DQA1.
Ostali aleli DQA1 nemaju definirani serotip. Postoji pet grupa: DQA1 *02, *03, *04, *05, *06. DQA1, a unutar ovih grupa su ili invarijantne ili proizvode istu podjedinicu α-lanca. DQA1*02 i DQA1*06 sadržeći samo jedan alel. DQA1*03 ima tri alela od kojih svaki proizvodi gotovo identične α3 . Za DQA1*05, DQA1*0501 i DQA1*0505 proizvode identične α5 . Postoje i drugi DQA1*05 koji proizvode varijantu α5var , ali oni su rijetki.
HLA-DQA1 pripada alfa lancu HLA klase II paraloga . Ova molekula klase II je heterodimer koji se sastoji od alfa (DQA) i beta lanca (DQB), oba usidrena u membrani. Ima centralnu ulogu u imunskom sistemu, predstavljajući peptide izvedene iz vanćelijskih proteina. Molekule klase II su eksprimirani u ćelijama koje prezentiraju antigen (APC: B-limfociti , dendritske ćelije , makrofagi ).[ 5]
^ a b c GRCh38: Ensembl release 89: ENSG00000274997 - Ensembl , maj 2017^ a b c GRCm38: Ensembl release 89: ENSMUSG00000069302 - Ensembl , maj 2017^ "Human PubMed Reference:" . National Center for Biotechnology Information, U.S. National Library of Medicine .^ "Mouse PubMed Reference:" . National Center for Biotechnology Information, U.S. National Library of Medicine .^ a b c "Entrez Gene: HLA-DQA1 major histocompatibility complex, class II, DQ alpha 1" .^ "UniProt, Q96KK5" (jezik: engleski). Pristupljeno 2. 10. 2021 .^ Lau M, Terasaki PI, Park MS (1994). "International Cell Exchange, 1994". Clin Transpl : 467–88. PMID 7547576 .
Schmidt H, Williamson D, Ashley-Koch A (2007). "HLA-DR15 haplotype and multiple sclerosis: a HuGE review" . Am. J. Epidemiol . 165 (10): 1097–109. doi :10.1093/aje/kwk118 PMID 17329717 . Marsh SG, Bodmer JG (1993). "HLA class II nucleotide sequences, 1992". Tissue Antigens . 40 (5): 229–43. doi :10.1111/j.1399-0039.1992.tb02050.x . PMID 1362295 . Piatier-Tonneau D, Gastinel LN, Amblard F, et al. (1991). "Interaction of CD4 with HLA class II antigens and HIV gp120" . Immunogenetics . 34 (2): 121–8. doi :10.1007/BF00211424 . PMID 1869305 . S2CID 10116507 . Rosenstein Y, Burakoff SJ, Herrmann SH (1990). "HIV-gp120 can block CD4-class II MHC-mediated adhesion". J. Immunol . 144 (2): 526–31. PMID 1967269 . Bowman MR, MacFerrin KD, Schreiber SL, Burakoff SJ (1991). "Identification and structural analysis of residues in the V1 region of CD4 involved in interaction with human immunodeficiency virus envelope glycoprotein gp120 and class II major histocompatibility complex molecules" . Proc. Natl. Acad. Sci. U.S.A . 87 (22): 9052–6. doi :10.1073/pnas.87.22.9052 PMC 55099 PMID 1978941 . Lee KW, Johnson AH, Hurley CK (1990). "Two divergent routes of evolution gave rise to the DRw13 haplotypes" . J. Immunol . 145 (9): 3119–25. PMID 2212675 . Todd JA, Fukui Y, Kitagawa T, Sasazuki T (1990). "The A3 allele of the HLA-DQA1 locus is associated with susceptibility to type 1 diabetes in Japanese" . Proc. Natl. Acad. Sci. U.S.A . 87 (3): 1094–8. Bibcode :1990PNAS...87.1094T . doi :10.1073/pnas.87.3.1094 PMC 53417 PMID 2300572 . Kao HT, Gregersen PK, Tang JC, et al. (1989). "Molecular analysis of the HLA class II genes in two DRw6-related haplotypes, DRw13 DQw1 and DRw14 DQw3" . J. Immunol . 142 (5): 1743–7. PMID 2493052 . Gyllensten UB, Erlich HA (1990). "Ancient roots for polymorphism at the HLA-DQ alpha locus in primates" . Proc. Natl. Acad. Sci. U.S.A . 86 (24): 9986–90. doi :10.1073/pnas.86.24.9986 PMC 298627 PMID 2513578 . Clayton LK, Sieh M, Pious DA, Reinherz EL (1989). "Identification of human CD4 residues affecting class II MHC versus HIV-1 gp120 binding" . Nature . 339 (6225): 548–51. Bibcode :1989Natur.339..548C . doi :10.1038/339548a0 PMID 2543930 . S2CID 4246781 . Jonsson AK, Andersson L, Rask L (1989). "Complete sequences of DQA1 and DQB1 cDNA clones corresponding to the DQw4 specificity" . Immunogenetics . 30 (3): 232–4. doi :10.1007/BF02421214 . PMID 2777341 . S2CID 28206170 . Diamond DC, Sleckman BP, Gregory T, et al. (1988). "Inhibition of CD4+ T cell function by the HIV envelope protein, gp120". J. Immunol . 141 (11): 3715–7. PMID 2846691 . Turco E, Care A, Compagnone-Post P, et al. (1987). "Allelic forms of the alpha- and beta-chain genes encoding DQw1-positive heterodimers". Immunogenetics . 26 (4–5): 282–90. doi :10.1007/BF00346523 . PMID 2888727 . S2CID 44734030 . Hurley CK, Gregersen P, Steiner N, et al. (1988). "Polymorphism of the HLA-D region in American blacks. A DR3 haplotype generated by recombination". J. Immunol . 140 (3): 885–92. PMID 2892884 . Jonsson AK, Hyldig-Nielsen JJ, Servenius B, et al. (1987). "Class II genes of the human major histocompatibility complex. Comparisons of the DQ and DX alpha and beta genes" . J. Biol. Chem . 262 (18): 8767–77. doi :10.1016/S0021-9258(18)47482-0 PMID 3036828 . Liu CP, Bach FH, Wu SK (1988). "Molecular studies of a rare DR2/LD-5a/DQw3 HLA class II haplotype. Multiple genetic mechanisms in the generation of polymorphic HLA class II genes" . J. Immunol . 140 (10): 3631–9. PMID 3129499 . Lock CB, So AK, Welsh KI, et al. (1988). "MHC class II sequences of an HLA-DR2 narcoleptic" . Immunogenetics . 27 (6): 449–55. doi :10.1007/BF00364432 . PMID 3259543 . S2CID 2338823 . Horn GT, Bugawan TL, Long CM, et al. (1988). "Sequence analysis of HLA class II genes from insulin-dependent diabetic individuals" . Hum. Immunol . 21 (4): 249–63. doi :10.1016/0198-8859(88)90034-1 . PMID 3372263 . Andrieu JM, Even P, Venet A (1986). "AIDS and related syndromes as a viral-induced autoimmune disease of the immune system: an anti-MHC II disorder. Therapeutic implications". AIDS Research . 2 (3): 163–74. doi :10.1089/aid.1.1986.2.163 . PMID 3489470 . Schiffenbauer J, Didier DK, Klearman M, et al. (1987). "Complete sequence of the HLA DQ alpha and DQ beta cDNA from a DR5/DQw3 cell line" . J. Immunol . 139 (1): 228–33. PMID 3584986 .
