KLF4(Kruppel like factor 4)は、ジンクフィンガー型転写因子であるKLFファミリー(英語版)の一員である。KLFファミリーはSp1様転写因子とともにSp1-like/KLFファミリーを構成する転写因子群である[5][6][7]。KLF4は細胞増殖、分化、アポトーシス、体細胞のリプログラミングの調節に関与している。また、KLF4は大腸がんなど特定のがんでがん抑制因子として機能することを示唆する証拠が得られている[8]。KLF4のC末端には3つのC2H2型ジンクフィンガーが存在し、これらはKLF2(英語版)と密接な関係にある[6]。また、2つの核局在配列が存在し、KLF4を細胞核へ局在させるシグナルとなっている[9]。胚性幹細胞では、KLF4は幹細胞性の良い指標となることが実証されている。このことは、間葉系幹細胞にも当てはまる。
^“Sp1 and krüppel-like factor family of transcription factors in cell growth regulation and cancer”. Journal of Cellular Physiology188 (2): 143–60. (August 2001). doi:10.1002/jcp.1111. PMID11424081.
^“A gene for a novel zinc-finger protein expressed in differentiated epithelial cells and transiently in certain mesenchymal cells”. The Journal of Biological Chemistry271 (49): 31384–90. (December 1996). doi:10.1074/jbc.271.49.31384. PMID8940147.
^“Kruppel-like factor 4 is acetylated by p300 and regulates gene transcription via modulation of histone acetylation”. The Journal of Biological Chemistry282 (47): 33994–4002. (November 2007). doi:10.1074/jbc.M701847200. PMID17908689.
^“Kruppel-like factor 4 (KLF4) represses histidine decarboxylase gene expression through an upstream Sp1 site and downstream gastrin responsive elements”. The Journal of Biological Chemistry279 (10): 8684–93. (March 2004). doi:10.1074/jbc.M308278200. PMID14670968.
^ ab“Kruppel-like factor 4 is a mediator of proinflammatory signaling in macrophages”. The Journal of Biological Chemistry280 (46): 38247–58. (November 2005). doi:10.1074/jbc.M509378200. PMID16169848.
^“Loss of Krüppel-like factor 4 expression contributes to Sp1 overexpression and human gastric cancer development and progression”. Clinical Cancer Research12 (21): 6395–402. (November 2006). doi:10.1158/1078-0432.CCR-06-1034. PMID17085651.
^ abc“The KLF4 tumour suppressor is a transcriptional repressor of p53 that acts as a context-dependent oncogene”. Nature Cell Biology7 (11): 1074–82. (November 2005). doi:10.1038/ncb1314. hdl:1874/17842. PMID16244670.
^ ab“KLF4 and KLF5 regulate proliferation, apoptosis and invasion in esophageal cancer cells”. Cancer Biology & Therapy4 (11): 1216–21. (November 2005). doi:10.4161/cbt.4.11.2090. PMID16357509.
^“[Effect of Krüppel-like factor 4 overexpression on heat stress-induced apoptosis of Raw264.7 macrophages]”. Zhong Nan da Xue Xue Bao. Yi Xue Ban = Journal of Central South University. Medical Sciences32 (6): 1002–6. (December 2007). PMID18182717.
^“Klf4 is a transcription factor required for establishing the barrier function of the skin”. Nature Genetics22 (4): 356–60. (August 1999). doi:10.1038/11926. PMID10431239.
^“Ectopic expression of kruppel like factor 4 (Klf4) accelerates formation of the epidermal permeability barrier”. Development130 (12): 2767–77. (June 2003). doi:10.1242/dev.00477. PMID12736219.
^“Krüppel-like factor 4 is widely expressed in the mouse male and female reproductive tract and responds as an immediate early gene to activation of the protein kinase A in TM4 Sertoli cells”. Reproduction139 (4): 771–82. (April 2010). doi:10.1530/REP-09-0531. PMID20051481.
^“Developmental and cell type-specific expression of the zinc finger transcription factor Krüppel-like factor 4 (Klf4) in postnatal mouse testis”. Mechanisms of Development115 (1–2): 167–9. (July 2002). doi:10.1016/s0925-4773(02)00127-2. PMID12049784.
^“Expression of CLMP, a novel tight junction protein, is mediated via the interaction of GATA with the Kruppel family proteins, KLF4 and Sp1, in mouse TM4 Sertoli cells”. Journal of Cellular Physiology214 (2): 334–44. (February 2008). doi:10.1002/jcp.21201. PMID17620326.
^“A functional screen for Krüppel-like factors that regulate the human gamma-globin gene through the CACCC promoter element”. Blood Cells, Molecules & Diseases35 (2): 227–35. (2005). doi:10.1016/j.bcmd.2005.04.009. PMID16023392.
^“KLF4 regulates the expression of interleukin-10 in RAW264.7 macrophages”. Biochemical and Biophysical Research Communications362 (3): 575–81. (October 2007). doi:10.1016/j.bbrc.2007.07.157. PMID17719562.
^“KLF4 is a FOXO target gene that suppresses B cell proliferation”. International Immunology20 (5): 671–81. (May 2008). doi:10.1093/intimm/dxn024. PMID18375530.
^“Renin-angiotensin blockade resets podocyte epigenome through Kruppel-like Factor 4 and attenuates proteinuria”. Kidney International88 (4): 745–53. (October 2015). doi:10.1038/ki.2015.178. PMID26108068.
^“The role of Krüppel-like factor 4 in transforming growth factor-β-induced inflammatory and fibrotic responses in human proximal tubule cells”. Clinical and Experimental Pharmacology & Physiology42 (6): 680–6. (June 2015). doi:10.1111/1440-1681.12405. PMID25882815.
^“Matrix-Stiffness-Regulated Inverse Expression of Krüppel-Like Factor 5 and Krüppel-Like Factor 4 in the Pathogenesis of Renal Fibrosis”. The American Journal of Pathology185 (9): 2468–81. (September 2015). doi:10.1016/j.ajpath.2015.05.019. PMID26212907.
^“Drastic down-regulation of Krüppel-like factor 4 expression is critical in human gastric cancer development and progression”. Cancer Research65 (7): 2746–54. (April 2005). doi:10.1158/0008-5472.CAN-04-3619. PMID15805274.
^“Downregulation and growth inhibitory effect of epithelial-type Krüppel-like transcription factor KLF4, but not KLF5, in bladder cancer”. Biochemical and Biophysical Research Communications308 (2): 251–6. (August 2003). doi:10.1016/s0006-291x(03)01356-1. PMID12901861.
^“Oncogene expression cloning by retroviral transduction of adenovirus E1A-immortalized rat kidney RK3E cells: transformation of a host with epithelial features by c-MYC and the zinc finger protein GKLF”. Cell Growth & Differentiation10 (6): 423–34. (June 1999). PMID10392904.
^“Increase of GKLF messenger RNA and protein expression during progression of breast cancer”. Cancer Research60 (22): 6488–95. (November 2000). PMID11103818.
^“Aldehyde dehydrogenase 1, a functional marker for identifying cancer stem cells in human nasopharyngeal carcinoma”. Cancer Letters330 (2): 181–9. (April 2013). doi:10.1016/j.canlet.2012.11.046. PMID23220285.
^“Wild-type p53 suppresses the epithelial-mesenchymal transition and stemness in PC-3 prostate cancer cells by modulating miR‑145”. International Journal of Oncology42 (4): 1473–81. (April 2013). doi:10.3892/ijo.2013.1825. PMID23404342.
^ ab“Krüppel-like factor 4 synergizes with CREB to increase the activity of apolipoprotein E gene promoter in macrophages”. Biochemical and Biophysical Research Communications468 (1–2): 66–72. (December 2015). doi:10.1016/j.bbrc.2015.10.163. PMID26546821.
“A gene for a novel zinc-finger protein expressed in differentiated epithelial cells and transiently in certain mesenchymal cells”. The Journal of Biological Chemistry271 (49): 31384–90. (December 1996). doi:10.1074/jbc.271.49.31384. PMID8940147.
“Human EZF, a Krüppel-like zinc finger protein, is expressed in vascular endothelial cells and contains transcriptional activation and repression domains”. The Journal of Biological Chemistry273 (2): 1026–31. (January 1998). doi:10.1074/jbc.273.2.1026. PMID9422764.
“Oncogene expression cloning by retroviral transduction of adenovirus E1A-immortalized rat kidney RK3E cells: transformation of a host with epithelial features by c-MYC and the zinc finger protein GKLF”. Cell Growth & Differentiation10 (6): 423–34. (June 1999). PMID10392904.
“Klf4 is a transcription factor required for establishing the barrier function of the skin”. Nature Genetics22 (4): 356–60. (August 1999). doi:10.1038/11926. PMID10431239.
“The Krüppel-like transcriptional factors Zf9 and GKLF coactivate the human keratin 4 promoter and physically interact”. FEBS Letters473 (1): 95–100. (May 2000). doi:10.1016/S0014-5793(00)01468-X. PMID10802067.
“Gut-enriched Kruppel-like factor represses ornithine decarboxylase gene expression and functions as checkpoint regulator in colonic cancer cells”. The Journal of Biological Chemistry277 (48): 46831–9. (November 2002). doi:10.1074/jbc.M204816200. PMID12297499.
“Transcriptional regulation of A33 antigen expression by gut-enriched Krüppel-like factor”. Oncogene22 (28): 4434–43. (July 2003). doi:10.1038/sj.onc.1206508. PMID12853980.
“Downregulation and growth inhibitory effect of epithelial-type Krüppel-like transcription factor KLF4, but not KLF5, in bladder cancer”. Biochemical and Biophysical Research Communications308 (2): 251–6. (August 2003). doi:10.1016/S0006-291X(03)01356-1. PMID12901861.
“Enterocyte differentiation marker intestinal alkaline phosphatase is a target gene of the gut-enriched Kruppel-like factor”. American Journal of Physiology. Gastrointestinal and Liver Physiology286 (1): G23-30. (January 2004). doi:10.1152/ajpgi.00203.2003. PMID12919939.