Trans-Regulatory KLF14 Gene: Comparison
Please note this is a comparison between Version 2 by Sirius Huang and Version 1 by Sumbal Rasheed.

Krüpple-Like family of transcription factor-14 (KLF14) is a master trans-regulatory gene that has multiple biological regulatory functions and is involved in many pathological mechanisms. It controls the expressions of several other genes which are involved in multiple regulatory functions. 

  • KLF14 gene
  • single nucleotide polymorphism
  • genetic variations
  • ApoA1
  • KLF14 gene polymorphism

1. Introduction

KLF14 is a member of the Krüpple-Like family of transcription factors [1,2][1][2], which regulates normal gene expression in mammals. In total, there are eighteen KLF proteins that are further grouped into three families. KLF14 activates transcription but also possesses a repressive role by interacting with Sin3A, which is a co-repressive protein in DNA [1]. KLFs have different patterns of expression in different body tissues by which many exhibit pronounced expressions, including KLF6 [3], KLF7 [4], KLF9 [5], KLF10 [6], KLF11 [7], KLF13 [8], and KLF15 [9]. While some members have tissue-specific expression, e.g., KLF1 expresses in megakaryocytes and red blood cells, KLF2 expresses in white adipose tissues, and KLF4 and KLF5 express in blood vessels and white adipose tissues [10].
KLF14 is a master trans-regulatory gene linked with the expression of various multiple metabolic traits. Mutations in master regulatory genes are often linked with the incidence of severe diseases as these genes regulate the concurrent expression of several genes [11]. Several kinds of metabolic disorders, including diabetes mellitus (DM), cardiovascular diseases (CVDs), and especially coronary artery diseases (CADs), are strongly linked with the variants near the KLF14 gene which is located on chromosome 7. KLF14 variants have more frequent expressions in women than in men. It has been evidenced from several studies that environmental factors directly influence the normal expression of the KLF14 gene and play a significant role in altered metabolic processes [10].
KLF proteins regulate several cell signaling pathways, including apoptosis, proliferation, and differentiation, etc. [1]. Only the maternal allele of KLF14 is expressed in humans and KLF14 expression has been found in many organs and tissues, including adipose tissues, the liver, the brain, and muscles [12]. KLF14 regulates insulin secretion, lipid metabolism, inflammatory responses, cell differentiation, and proliferation. Therefore, it is proven as a potential target to reduce the risk of CVDs [13]. Moreover, KLF14 regulates the efflux of HDL-C and ApoA-1; therefore, alterations in the normal expression of KLF14 triggered by gene polymorphism or epigenetic alteration induce the onset of metabolic disorders [14]. Several KLF14 variants have been identified using genome-wide association studies (GWASs), which lead toward the altered insulin sensitivity, development, and progression of several metabolic diseases, including DM, myocardial infarction, atherosclerotic cardiac diseases, and ischemic stroke [15,16,17,18][15][16][17][18]. Interestingly, single-nucleotide polymorphisms (SNPs) of KLF14 were significantly found in adipose tissues [15,19][15][19]. KLF14 has different CpG sites which can be hypermethylated over age, thus KLF14 can be used to estimate the chronological age and serve as an age-related epigenetic biomarker [20]. KLF14 is widely expressed in various tissues, and its role in different altered metabolic processes has been reviewed. Researchers have previously worked on genetic polymorphism of different genes, including FTO, PPAR-γ, ABCC8, APOEε4, AGT, and MTHFR genes [21,22,23,24][21][22][23][24]

2. Configuration and Expression of the KLF14 Gene

KLF proteins bind with the regulatory regions of a targeted gene as these proteins have conserved C2H2-type zinc finger domains at their C-terminal, which is involved in binding with the GC-rich regions of the genes [1]. The KLF14 protein retains three C2H2-type zinc finger structural motifs in C-terminus with two domains (first and second) and a short third domain encompassing 25 and 23 amino acid residues, receptively [25,26][25][26]. These three zinc finger domains can identify three DNA base pairs, and thus have an affinity to bind at three sites in the gene regulatory region [27]. Moreover, it has been found that these domains possess positively charged amino acids which may assist in the localization of the nucleus. Several investigational studies concluded that KLF proteins can interact with similar GC-rich sequences or 5′-CACCC-3′ of several genes’ promoter regions [28,29][28][29]. KLF proteins show binding affinity with other proteins’ associates such as co-repressors, histone-modifying enzymes, and co-activators, etc., due to their N-terminus regions [30].
The transcriptional target sites of KLF14 are not well described however, few studies have identified different targets. Liver-specific KLF14 knockout in mouse models causes ApoA-1 deficiency, which indicates that KLF14 is involved in the transcriptional regulation of ApoA-1 [31]. Therefore, ApoA-1 is an important target of KLF14. There are two binding sites for KLF14 on the promoter region of ApoA-1 in humans. Sphingosine kinase 1 (SK1) is also a functional transcriptional target of KLF14. KLF14 suppresses the transcription of SK1 by binding with its promoter region [32]. One study demonstrated that KLF14 at the FOXP3 Treg-specific demethylation region remolds the chromatin and, as a result, regulates T-cell differentiation [33].
Trans-regulated genes’ promoter regions have enriched binding motifs for KLF14 [10]. These trans-genes regulate the MetSyn such as IDE, a regulator of insulin degradation [34], SLC2A4, which regulates the expression of GLUT4 protein which is responsible for insulin-induced glucose uptake in muscles and adipose tissues [35], and STARD10 which regulates insulin secretion in β-cells of pancreatic islets [36,37][36][37] as shown in Table 1. Moreover, KLF14 regulates the MAPK proteins level as KLF14 knockout results in the elevated level of MAPK proteins, including p38 and ERK1/2, which are associated with the regulation of several pro-inflammatory factors [38].
Table 1.
Impact and ultimate consequences of KLF14 genetic variants on Trans-regulatory genes.

3. KLF14 Trans-Regulatory Network

The KLF14 gene is located on chromosome 7q32.3. Out of 82 KLF14-linked transcriptional factors, only 62 have been identified in humans. Transcriptional factors are specialized proteins that control gene expression. These factors are encoded by different genes, including HOXA9, HOXA3, and AHR. The Sin2A protein represses transcription, which leads to the transcriptional repression of important enzymatic proteins such as HDAC1 and HDAC2, DNA binding proteins, such as Mas and MeCP2, and the co-repressor proteins Ikaros and SMRT [42,43][42][43].
The major family of transcriptional factors, including sequence-specific DNA proteins and genes, have an important role in the regulation of different body functions, including CNS development (EN1), hematopoiesis (EVI1), cell growth regulation (MEF2A), regeneration of muscle (MYOD1), cell apoptosis (EVI1, MEF2A), and erythroid development (GATA1), and are vital in normal growth (MEIS1), hematopoietic proliferation and development, and endocrine cell lineage (GATA2), and embryonic regulation (FOXC1), etc. Interestingly, important genes that are involved in the pathogenesis of metabolic disorders such as the TCF7L2 and PPARG genes are not included among these genes.
The trans-acting regulator, encoded by the KLF14 gene regulates the expression of a cluster of genes that are involved with the metabolic phenotypes, including HDL level, insulin and glucose levels, LDL level, TG level, BMI, and insulin sensitivity index, etc. [11]. The resultant product (transcriptional factor) of KLF14 gene transcription interacts with 10 genes and establishes the protein–protein interactions with 32 proteins, which have a strong association with metabolic disorders and several other biological functions [44]. These 32 proteins, including CKAL1, KCNQ1, IGF2BP2, etc., have shown significant interaction with the KLF14 protein. Studies have shown that the KLF14 protein interacts with UBC (polyubiquitin precursor) which regulates the cell cycle, endocytosis, apoptosis, cell signaling pathways, DNA repair, and protein trafficking, etc. [11].


  1. McConnell, B.B.; Yang, V.W.; Mallipattu, S.K.; Estrada, C.C.; He, J.C.; Talmasov, D.; Zhang, X.; Yu, B.; Nandan, M.O.; Bialkowska, A.B.; et al. Mammalian Krüppel-Like Factors in Health and Diseases. Physiol. Rev. 2010, 90, 1337–1381.
  2. Tetreault, M.P.; Yang, Y.; Katz, J.P. Krüppel-like factors in cancer. Nat. Rev. Cancer 2013, 13, 701–713.
  3. Matsumoto, N.; Kubo, A.; Liu, H.; Akita, K.; Laub, F.; Ramirez, F. Developmental regulation of yolk sac hematopoiesis by Kruppel-like factor 6. Blood 2006, 107, 1357–1365.
  4. Laub, F.; Lei, L.; Sumiyoshi, H.; Kajimura, D.; Dragomir, C.; Smaldone, S.; Puche, A.C.; Petros, T.J.; Mason, C.; Parada, L.F.; et al. Transcription Factor KLF7 Is Important for Neuronal Morphogenesis in Selected Regions of the Nervous System. Mol. Cells Biol. 2005, 25, 5699–5711.
  5. Morita, M.; Kobayashi, A.; Yamashita, T.; Shimanuki, T.; Nakajima, O.; Takahashi, S.; Ikegami, S.; Inokuchi, K.; Yamashita, K.; Yamamoto, M.; et al. Functional Analysis of Basic Transcription Element Binding Protein by Gene Targeting Technology. Mol. Cells Biol. 2003, 23, 2489–2500.
  6. Subramaniam, M.; Gorny, G.; Johnsen, S.A.; Monroe, D.G.; Evans, G.L.; Fraser, D.G.; Rickard, D.J.; Rasmussen, K.; van Deursen, J.M.A.; Turner, R.T.; et al. TIEG1 Null Mouse-Derived Osteoblasts Are Defective in Mineralization and in Support of Osteoclast Differentiation In Vitro. Mol. Cells Biol. 2005, 25, 1191–1199.
  7. Song, C.-Z.; Gavriilidis, G.; Asano, H.; Stamatoyannopoulos, G. Functional study of transcription factor KLF11 by targeted gene inactivation. Blood Cells Mol. Dis. 2005, 34, 53–59.
  8. Zhou, M.; McPherson, L.; Feng, D.; Song, A.; Dong, C.; Lyu, S.C.; Krensky, A.M. Kruppel-like transcription factor 13 regulates T lymphocyte survival in vivo. J. Immunol. 2007, 178, 5496–5504.
  9. Fisch, S.; Gray, S.; Heymans, S.; Haldar, S.M.; Wang, B.; Pfister, O.; Jain, M.K. Kruppel-like factor 15 is a regulator of cardiomyocyte hypertrophy. Proc. Natl. Acad. Sci. USA 2007, 104, 7074–7079.
  10. Yang, Q.; Civelek, M. Transcription Factor KLF14 and Metabolic Syndrome. Front. Cardiovasc. Med. 2020, 7, 91.
  11. Fokeng, M.G.; Atogho-Tiedeu, B.; Sobngwi, E. The Krüppel-like factor 14 (KLF14), master gene of multiple metabolic phenotypes: Putative TransRegulator Network. Transl. Biomed. 2016, 7, 2.
  12. Parker-Katiraee, L.; Carson, A.R.; Yamada, T.; Arnaud, P.; Feil, R.; Abu-Amero, S.N.; Scherer, S.W. Identification of the imprinted KLF14 transcription factor undergoing human-specific accelerated evolution. PLoS Genet. 2007, 3, e65.
  13. Xie, W.; Li, L.; Zheng, X.-L.; Yin, W.-D.; Tang, C.-K. The role of Krüppel-like factor 14 in the pathogenesis of atherosclerosis. Atherosclerosis 2017, 263, 352–360.
  14. Wu, S.; Hsu, L.-A.; Teng, M.-S.; Chou, H.-H.; Ko, Y.-L. Differential Genetic and Epigenetic Effects of the KLF14 Gene on Body Shape Indices and Metabolic Traits. Int. J. Mol. Sci. 2022, 23, 4165.
  15. Small, K.S.; Todorčević, M.; Civelek, M.; El-Sayed Moustafa, J.S.; Wang, X.; Simon, M.M.; McCarthy, M.I. Regulatory variants at KLF14 influence type 2 diabetes risk via a female-specific effect on adipocyte size and body composition. Nat. Genet. 2018, 50, 572–580.
  16. Chen, X.; Li, S.; Yang, Y.; Yang, X.; Liu, Y.; Hu, W.; Jin, L.; Wang, X. Genome-wide association study validation identifies novel loci for atherosclerotic cardiovascular disease. J. Thromb. Haemost. 2012, 10, 1508–1514.
  17. Teslovich, T.M.; Musunuru, K.; Smith, A.V.; Edmondson, A.C.; Stylianou, I.M.; Koseki, M.; Pirruccello, J.P.; Ripatti, S.; Chasman, D.I.; Willer, C.J.; et al. Biological, clinical and population relevance of 95 loci for blood lipids. Nature 2010, 466, 707–713.
  18. Voight, B.F.; Scott, L.J.; Steinthorsdottir, V.; Morris, A.P.; Dina, C.; Welch, R.P.; Zeggini, E.; Huth, C.; Aulchenko, Y.S.; Thorleifsson, G.; et al. Twelve type 2 diabetes susceptibility loci identified through large-scale association analysis. Nat. Genet. 2010, 42, 579–589, Corrigendum on Nat. Genet. 2011, 43, 388.
  19. Civelek, M.; Wu, Y.; Pan, C.; Raulerson, C.; Ko, A.; He, A.; Tilford, C.; Saleem, N.K.; Stančáková, A.; Scott, L.J.; et al. Genetic Regulation of Adipose Gene Expression and Cardio-Metabolic Traits. Am. J. Hum. Genet. 2017, 100, 428–443.
  20. Mugatroyd, C.; Wu, Y.; Bockmühl, Y.; Spengler, D. The Janus face of DNA methylation in aging. Aging 2010, 2, 107–110.
  21. Rehman, K.; Niaz, S.; Tahir, A.; Jabeen, K. Akash MSH. FTO, PPAR-γ and ABCC8 gene variation and hypertension as de-terminants of cardiometabolic risk in CVD patients. Metab. Clin. Exp. 2022, 128, 154972.
  22. Jabeen, K.; Rehman, K.; Akash, M.S.H. Genetic mutations of APOEε4 carriers in cardiovascular patients lead to the de-velopment of insulin resistance and risk of Alzheimer’s disease. J. Biochem. Mol. Toxicol. 2022, 36, e22953.
  23. Shahid, M.; Rehman, K.; Akash, M.S.H. Suhail S, Kamal S, Imran M, Assiri MA. Genetic polymorphism in angiotensinogen and its association with cardiometabolic diseases. Metabolites 2022, 12, 1291.
  24. Shahid, M.; Rehman, K.; Akash, M.S.H. Suhail S, Rasheed S, Imran M, Assiri MA. Biochemical association between the prevalence of genetic polymorphism and myocardial infarction. Biocells 2023, 47, 473–484.
  25. Krishna, S.S.; Majumdar, I.; Grishin, N.V. Structural classification of zinc fingers: Survey and summary. Nucleic Acids Res. 2003, 31, 532–550.
  26. Scohy, S.; Gabant, P.; Van Reeth, T.; Hertveldt, V.; Drèze, P.-L.; Van Vooren, P.; Rivière, M.; Szpirer, J.; Szpirer, C. Identification of KLF13 and KLF14 (SP6), Novel Members of the SP/XKLF Transcription Factor Family. Genomics 2000, 70, 93–101.
  27. Nagai, R.; Friedman, S.L.; Kasuga, M. The Biology of Krüppel-Like Factors; Springer: Berlin/Heidelberg, Germany, 2009.
  28. Pandya, A.Y.; Talley, L.I.; Frost, A.R.; Fitzgerald, T.J.; Trivedi, V.; Chakravarthy, M.; Chhieng, D.C.; Grizzle, W.E.; Engler, J.A.; Krontiras, H.; et al. Nuclear Localization of KLF4 Is Associated with an Aggressive Phenotype in Early-Stage Breast Cancer. Clin. Cancer Res. 2004, 10, 2709–2719.
  29. Quadrini, K.J.; Bieker, J.J. Krüppel-like Zinc Fingers Bind to Nuclear Import Proteins and Are Required for Efficient Nuclear Localization of Erythroid Krüppel-like Factor. J. Biol. Chem. 2002, 277, 32243–32252.
  30. Dereeper, A.; Guignon, V.; Blanc, G.; Audic, S.; Buffet, S.; Chevenet, F.; Dufayard, J.-F.; Guindon, S.; Lefort, V.; Lescot, M.; et al. Robust phylogenetic analysis for the non-specialist. Nucleic Acids Res. 2008, 36, W465–W469.
  31. Guo, Y.; Fan, Y.; Zhang, J.; Lomberk, G.A.; Zhou, Z.; Sun, L.; Chen, Y.E. Perhexiline activates KLF14 and reduces atherosclerosis by modulating ApoA-I production. J. Clin. Investig. 2015, 125, 3819–3830.
  32. de Assuncao, T.M.; Lomberk, G.; Cao, S.; Yaqoob, U.; Mathison, A.; Simonetto, D.A.; Shah, V.H. New role for Kruppel-like factor 14 as a transcriptional activator involved in the generation of signaling lipids. J. Biol. Chem. 2014, 289, 15798–15809.
  33. Sarmento, O.F.; Svingen, P.A.; Xiong, Y.; Xavier, R.J.; McGovern, D.; Smyrk, T.C. A novel role for KLF14 in T regulatory cell differentiation. Cell. Mol. Gastroenterol. Hepatol. 2015, 1, 188–202.e4.
  34. Farris, W.; Mansourian, S.; Chang, Y.; Lindsley, L.; Eckman, E.A.; Frosch, M.P. Insulin-degrading enzyme regulates the levels of insulin, amyloid beta-protein, and the beta-amyloid precursor protein intracellular domain in vivo. Proc. Natl. Acad. Sci. USA 2003, 100, 4162–4167.
  35. Nakata, M.; Nagasaka, S.; Kusaka, I.; Matsuoka, H.; Ishibashi, S.; Yada, T. Effects of statins on the adipocyte maturation and expression of glucose transporter 4 (SLC2A4): Implications in glycaemic control. Diabetologia 2006, 49, 1881–1892.
  36. Carrat, G.R.; Hu, M.; Nguyen-Tu, M.-S.; Chabosseau, P.; Gaulton, K.J.; van de Bunt, M.; Siddiq, A.; Falchi, M.; Thurner, M.; Canouil, M.; et al. Decreased STARD10 Expression Is Associated with Defective Insulin Secretion in Humans and Mice. Am. J. Hum. Genet. 2017, 100, 238–256.
  37. Hu, M.; Gadue, P.; Rutter, G.A. Characterization of a type 2 diabetes–associated islet-specific enhancer cluster in STARD10 by genome editing of endoC-ßH1 cells. Diabetes 2018, 67 (Suppl. 1), 1708.
  38. Wei, X.; Yang, R.; Wang, C.; Jian, X.; Li, L.; Liu, H.; Yang, G.; Li, Z. A novel role for the Krüppel-like factor 14 on macrophage inflammatory response and atherosclerosis development. Cardiovasc. Pathol. 2017, 27, 1–8.
  39. Steneberg, P.; Bernardo, L.; Edfalk, S.; Lundberg, L.; Backlund, F.; Östenson, C.-G. The Type 2 Diabetes–Associated Gene Ide Is Required for Insulin Secretion and Suppression of α-Synuclein Levels in β-Cells. Diabetes 2013, 62, 2004–2014.
  40. Corrêa-Giannella, M.L.; Machado, U.F. SLC2A4 gene: A promising target for pharmacogenomics of insulin resistance. Pharmacogenomics 2013, 14, 847–850.
  41. Carrat, G.R.; Haythorne, E.; Tomas, A.; Haataja, L.; Müller, A.; Arvan, P.; Piunti, A.; Cheng, K.; Huang, M.; Pullen, T.J.; et al. The type 2 diabetes gene product STARD10 is a phosphoinositide-binding protein that controls insulin secretory granule biogenesis. Mol. Metab. 2020, 40, 101015.
  42. Cunliffe, V.T. Eloquent silence: Developmental functions of Class I histone deacetylases. Curr. Opin. Genet. Dev. 2008, 18, 404–410.
  43. Kadosh, D.; Struhl, K. Histone deacetylase activity of Rpd3 is important for transcriptional repression in vivo. Genes Dev. 1998, 12, 797–805.
  44. Cauchi, S.; Meyre, D.; Dina, C.; Choquet, H.; Samson, C.; Gallina, S.; Froguel, P. Transcription factor TCF7L2 genetic study in the French population: Expression in human beta-cells and adipose tissue and strong association with type 2 diabetes. Diabetes 2006, 55, 2903–2908.