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PITX2

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这是本页的一个历史版本,由Kaguya-Taketori留言 | 贡献2017年9月25日 (一) 07:49 建立内容为“{{Infobox_gene}} '''''PITX2''''''(Paired-like homeodomain transcription factor 2(類成對同源框轉錄因子2)/pituitary homeobox 2(垂…”的新页面)编辑。这可能和当前版本存在着巨大的差异。

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PITX2
已知的結構
PDB直系同源搜索: PDBe RCSB
識別號
别名PITX2;, ARP1, Brx1, IDG2, IGDS, IGDS2, IHG2, IRID2, Otlx2, PTX2, RGS, RIEG, RIEG1, RS, paired like homeodomain 2, ASGD4
外部IDOMIM601542 MGI109340 HomoloGene55454 GeneCardsPITX2
相關疾病
Axenfeld-Rieger syndrome type 1、​虹膜發育不良綜合徵、​ring dermoid of cornea、​Rieger anomaly[1]
基因位置(人类
4號染色體
染色体4號染色體[2]
4號染色體
PITX2的基因位置
PITX2的基因位置
基因座4q25起始110,617,423 bp[2]
终止110,642,123 bp[2]
RNA表达模式
查阅更多表达数据
直系同源
物種人類小鼠
Entrez
Ensembl
UniProt
mRNA​序列

NM_001042502
​NM_001042504
​NM_001286942
​NM_001287048
​NM_011098

蛋白序列

NP_001035967
​NP_001035969
​NP_001273871
​NP_001273977
​NP_035228

基因位置​(UCSC)Chr 4: 110.62 – 110.64 MbChr 3: 128.99 – 129.01 Mb
PubMed​查找[4][5]
維基數據
檢視/編輯人類檢視/編輯小鼠

PITX2'(Paired-like homeodomain transcription factor 2(類成對同源框轉錄因子2)/pituitary homeobox 2(垂體同源框2))是一個位於人第四號染色體上的基因,由其編碼的蛋白為PITX2[6][7][8]

功能

PITX2蛋白屬於RIEG/PITX同源框蛋白家族,有一個屬於Bicoid英语Bicoid蛋白家族的同源結構域。從功能上說,PITX2是一種轉錄因子[9],主要調控{{link-en|賴氨酰羥化酶|lysyl hydroxylase|前膠原賴氨酰羥化酶(procollagen lysyl hydroxylase)基因的表達。賴氨酰羥化酶參與眼、牙,以及腹部器官的發育過程。PITX2的轉錄調節火星受到催乳素的調節。 已發現人體內的PITX2有三種轉錄變體[8]

PITX2在發育中與左—右軸的建立及左右不對稱性的形成有關,比如左側中胚層、心臟、肺、脾的不對稱發育及早起胃腸道的彎折。已證明在非人脊椎動物中,PITX2的同源基因亦有這樣的功能。敲除小鼠的Pitx2基因後,會導致身體左側器官形態發育異常。PITX2本身的表達受到ASE增強子和NODAL英语NODAL蛋白的調控。目前的研究證據顯示NODAL蛋白主要調控頭部的PITX2基因表達,而ASE主要調控控制不對稱發展的PITX2基因的發展,如肝、脾的不對稱發展。在眼部發育中,PITX2能抑制眼外肌的自噬,並能控制其生長[10][11][12]。PITX2的三種轉錄變體PITX2a、PITX2b、PITX2c各自都有不重疊的不同功能.[13]

PITX2亦參與了附肢形態形成。PITX2能調控MyoD基因的表達,使其在附肢形成過程中一直表達。MyoD基因與骨骼形態發生有關。研究表明Pixt2在肌肉中先於MyoD表達。要激活MyoD基因表達,PITX2首先會募集到MyoD的核心增強子上,然後激活MyoD的表達。Myf5、Myf6基因亦能調控MyoD的表達,但與PITX2之間互不影響。PITX2對附肢發育的調控依賴PAX3蛋白。在缺乏PAX3的情況下,即使PITX2表達附肢也無法形成。該實驗結果提示在調控通路中PITX2處於PAX3的下游,充當了PAX3和MyoD之間的中間體。總而言之,PITX2在附肢發育中是不可或缺的[14]


另外,有證據表明Pitx2在大鼠體內與性腺聲稱障礙有關[15]

已隱藏部分未翻譯内容,歡迎參與翻譯

Clinical significance

Mutations in this gene are associated with Axenfeld-Rieger syndrome (ARS), iridogoniodysgenesis syndrome (IGDS), and sporadic cases of Peters anomaly. This protein plays a role in the terminal differentiation of somatotroph and lactotroph cell phenotypes.[8]

Pitx2 is overexpressed in many cancers. For example, thyroid,[16] ovarian,[17] and colon cancer[18] all have higher levels of Pitx2 compared to noncancerous tissues. Scientists speculate that cancer cells improperly turn on Pitx2, leading to uncontrolled cell proliferation. This is consistent with the role of Pitx2 in regulating the growth-regulating genes cyclin D2,[19] cyclin D1,[20] and C-Myc.[20]

In renal cancer, Pitx2 regulates expression of ABCB1, a multidrug transporter, by binding to the promoter region of ABCB1.[21] Increased expression of Pitx2 in renal cancer cells is associated with increased expression of ABCB1.[21] Thus, renal cancer cells that overexpress ABCB1 have a greater resistance to chemotherapeutic agents.[21] In experiments where Pitx2 expression was decreased, renal cancer cells had decreased cell proliferation and greater susceptibility to doxorubicin treatment, which is consistent with other results.[21]

In human esophageal squamous cell carcinoma (ESCC), Pitx2 is overexpressed compared to normal esophageal squamous cells.[22] In addition, greater expression of Pitx2 is positively correlated with clinical aggressiveness of ESCC.[22] Also, ESCC patients with high Pitx2 expression did not respond as well to definitive chemoradiotherapy (CRT) compared to ESCC patients with low Pitx2 expression.[22] Thus, physicians may be able to use Pitx2 expression to predict how ESCC patients will respond to cancer treatment.[22]

In Congenital Heart Disease, heterozygous mutations in Pitx2 have been involved in the development of Tetralogy of Fallot, ventricular septal defects, atrial septal defects, transposition of great arteries, and endocardial cushion defect (ECD).[23][24][25] The mutations of the Pitx2 gene are created through alternative splicing. The isoform of Pitx2 important for cardiogenesis is Pitx2c. The lack of expression of this particular isoform correlates with these congenital defects. Pitx2 mutations significantly reduce transcriptional activity of Pitx2 and synergistic activation between Pitx2 and NKX2(also important for development of the heart).[23] The large phenotypic spectrum due to the mutation of Pitx2 may be attributed to a variety of factors including: different genetic backgrounds, epigenetic modifiers and delayed/complete penetrance.[24] It is important to note that the mutation of Pitx2 is not defined as the cause of these congenital heart defects, but currently perceived as a risk factor for their development.[25]

參考

  1. ^ 與PITX2相關的疾病;在維基數據上查看/編輯參考. 
  2. ^ 2.0 2.1 2.2 GRCh38: Ensembl release 89: ENSG00000164093 - Ensembl, May 2017
  3. ^ 3.0 3.1 3.2 GRCm38: Ensembl release 89: ENSMUSG00000028023 - Ensembl, May 2017
  4. ^ Human PubMed Reference:. National Center for Biotechnology Information, U.S. National Library of Medicine. 
  5. ^ Mouse PubMed Reference:. National Center for Biotechnology Information, U.S. National Library of Medicine. 
  6. ^ Arakawa H, Nakamura T, Zhadanov AB, Fidanza V, Yano T, Bullrich F, Shimizu M, Blechman J, Mazo A, Canaani E, Croce CM. Identification and characterization of the ARP1 gene, a target for the human acute leukemia ALL1 gene. Proceedings of the National Academy of Sciences of the United States of America. Apr 1998, 95 (8): 4573–8. PMC 22531可免费查阅. PMID 9539779. doi:10.1073/pnas.95.8.4573. 
  7. ^ Héon E, Sheth BP, Kalenak JW, Sunden SL, Streb LM, Taylor CM, Alward WL, Sheffield VC, Stone EM. Linkage of autosomal dominant iris hypoplasia to the region of the Rieger syndrome locus (4q25). Human Molecular Genetics. Aug 1995, 4 (8): 1435–9. PMID 7581385. doi:10.1093/hmg/4.8.1435. 
  8. ^ 8.0 8.1 8.2 Entrez Gene: PITX2 paired-like homeodomain transcription factor 2. 
  9. ^ Logan M, Pagán-Westphal SM, Smith DM, Paganessi L, Tabin CJ. The transcription factor Pitx2 mediates situs-specific morphogenesis in response to left-right asymmetric signals. Cell. Aug 1998, 94 (3): 307–17. PMID 9708733. doi:10.1016/S0092-8674(00)81474-9. 
  10. ^ Campione M, Steinbeisser H, Schweickert A, Deissler K, van Bebber F, Lowe LA, Nowotschin S, Viebahn C, Haffter P, Kuehn MR, Blum M. The homeobox gene Pitx2: mediator of asymmetric left-right signaling in vertebrate heart and gut looping. Development. Mar 1999, 126 (6): 1225–34. PMID 10021341. 
  11. ^ Shiratori H, Yashiro K, Shen MM, Hamada H. Conserved regulation and role of Pitx2 in situs-specific morphogenesis of visceral organs. Development. Aug 2006, 133 (15): 3015–25. PMID 16835440. doi:10.1242/dev.02470. 
  12. ^ Zacharias AL, Lewandoski M, Rudnicki MA, Gage PJ. Pitx2 is an upstream activator of extraocular myogenesis and survival. Developmental Biology. Jan 2011, 349 (2): 395–405. PMC 3019256可免费查阅. PMID 21035439. doi:10.1016/j.ydbio.2010.10.028. 
  13. ^ Essner JJ, Branford WW, Zhang J, Yost HJ. Mesendoderm and left-right brain, heart and gut development are differentially regulated by pitx2 isoforms. Development. Mar 2000, 127 (5): 1081–93. PMID 10662647. 
  14. ^ L'honoré A, Ouimette JF, Lavertu-Jolin M, Drouin J. Pitx2 defines alternate pathways acting through MyoD during limb and somitic myogenesis. Development. Nov 2010, 137 (22): 3847–56. PMID 20978076. doi:10.1242/dev.053421. 
  15. ^ Nandi SS, Ghosh P, Roy SS. Expression of PITX2 homeodomain transcription factor during rat gonadal development in a sexually dimorphic manner. Cellular Physiology and Biochemistry. 2011, 27 (2): 159–70. PMID 21325833. doi:10.1159/000325218. 
  16. ^ Huang Y, Guigon CJ, Fan J, Cheng SY, Zhu GZ. Pituitary homeobox 2 (PITX2) promotes thyroid carcinogenesis by activation of cyclin D2. Cell Cycle. Apr 2010, 9 (7): 1333–41. PMID 20372070. doi:10.4161/cc.9.7.11126. 
  17. ^ Fung FK, Chan DW, Liu VW, Leung TH, Cheung AN, Ngan HY. Increased expression of PITX2 transcription factor contributes to ovarian cancer progression. PLOS ONE. 2012, 7 (5): e37076. PMC 3352869可免费查阅. PMID 22615897. doi:10.1371/journal.pone.0037076. 
  18. ^ Hirose H, Ishii H, Mimori K, Tanaka F, Takemasa I, Mizushima T, Ikeda M, Yamamoto H, Sekimoto M, Doki Y, Mori M. The significance of PITX2 overexpression in human colorectal cancer. Annals of Surgical Oncology. Oct 2011, 18 (10): 3005–12. PMID 21479692. doi:10.1245/s10434-011-1653-z. 
  19. ^ Kioussi C, Briata P, Baek SH, Rose DW, Hamblet NS, Herman T, Ohgi KA, Lin C, Gleiberman A, Wang J, Brault V, Ruiz-Lozano P, Nguyen HD, Kemler R, Glass CK, Wynshaw-Boris A, Rosenfeld MG. Identification of a Wnt/Dvl/beta-Catenin --> Pitx2 pathway mediating cell-type-specific proliferation during development. Cell. Nov 2002, 111 (5): 673–85. PMID 12464179. doi:10.1016/s0092-8674(02)01084-x. 
  20. ^ 20.0 20.1 Baek SH, Kioussi C, Briata P, Wang D, Nguyen HD, Ohgi KA, Glass CK, Wynshaw-Boris A, Rose DW, Rosenfeld MG. Regulated subset of G1 growth-control genes in response to derepression by the Wnt pathway. Proceedings of the National Academy of Sciences of the United States of America. Mar 2003, 100 (6): 3245–3250. PMC 152277可免费查阅. PMID 12629224. doi:10.1073/pnas.0330217100. 
  21. ^ 21.0 21.1 21.2 21.3 Lee WK, Chakraborty PK, Thévenod F. Pituitary homeobox 2 (PITX2) protects renal cancer cell lines against doxorubicin toxicity by transcriptional activation of the multidrug transporter ABCB1. International Journal of Cancer. Journal International Du Cancer. Aug 2013, 133 (3): 556–67. PMID 23354914. doi:10.1002/ijc.28060. 
  22. ^ 22.0 22.1 22.2 22.3 Zhang JX, Tong ZT, Yang L, Wang F, Chai HP, Zhang F, Xie MR, Zhang AL, Wu LM, Hong H, Yin L, Wang H, Wang HY, Zhao Y. PITX2: a promising predictive biomarker of patients' prognosis and chemoradioresistance in esophageal squamous cell carcinoma. International Journal of Cancer. Journal International Du Cancer. Jun 2013, 132 (11): 2567–2577. PMID 23132660. doi:10.1002/ijc.27930. 
  23. ^ 23.0 23.1 Sun, Y. PITX2 loss-of-function mutation contributes to tetralogy of Fallot. Gene. February 15, 2016, 577: 258–264. PMID 26657035. doi:10.1016/j.gene.2015.12.001. 
  24. ^ 24.0 24.1 Zhao, C. PITX2 Loss-of-Function Mutation contributes to Congenital Endocardial Cushion Defect and Axenfold-Rieger Syndrome. PLOS ONE. April 20, 2015, 10: e0124409. PMC 4404345可免费查阅. PMID 25893250. doi:10.1371/journal.pone.0124409. 
  25. ^ 25.0 25.1 Dong, Wei. Novel Pitx2c loss-of-function mutations associated with complex congenital heart disease. International Journal of Molecular Medicine. January 14, 2014. doi:10.3892/ijmm.2014.168. 

拓展閱讀

外部連結


PITX2引用了美国国家医学图书馆提供的資料,这些資料属于公共领域