Carbohydrate-responsive element-binding protein (ChREBP) also known as MLX-interacting protein-like (MLXIPL) is a protein that in humans is encoded by the MLXIPLgene.[1][2] The protein name derives from the protein's interaction with carbohydrate response element sequences of DNA.
This gene encodes a basic helix-loop-helix leucine zipper transcription factor of the Myc / Max / Mad superfamily. This protein forms a heterodimeric complex and binds and activates, in a glucose-dependent manner, carbohydrate response element (ChoRE) motifs in the promoters of triglyceride synthesis genes.[2]
Clinical significance
This gene is deleted in Williams-Beuren syndrome, a multisystem developmental disorder caused by the deletion of contiguous genes at chromosome 7q11.23.[2]
ChREBP is translocated to the nucleus and binds to DNA after dephosphorylation of a p-Ser and a p-Thr residue by PP2A, which itself is activated by Xylulose-5-phosphate. Xu5p is produced in the pentose phosphate pathway when levels of Glucose-6-phosphate are high (the cell has ample glucose). In the liver, ChREBP mediates activation of several regulatory enzymes of glycolysis and lipogenesis including L-type pyruvate kinase (L-PK), acetyl CoA carboxylase, and fatty acid synthase.
References
↑Meng X, Lu X, Li Z, Green ED, Massa H, Trask BJ, Morris CA, Keating MT (Jan 1999). "Complete physical map of the common deletion region in Williams syndrome and identification and characterization of three novel genes". Hum Genet. 103 (5): 590–9. doi:10.1007/s004390050874. PMID9860302.
↑Cairo S, Merla G, Urbinati F, Ballabio A, Reymond A (March 2001). "WBSCR14, a gene mapping to the Williams--Beuren syndrome deleted region, is a new member of the Mlx transcription factor network". Hum. Mol. Genet. 10 (6): 617–27. doi:10.1093/hmg/10.6.617. PMID11230181.
Further reading
de Luis O, Valero MC, Jurado LA (2000). "WBSCR14, a putative transcription factor gene deleted in Williams-Beuren syndrome: complete characterisation of the human gene and the mouse ortholog". Eur. J. Hum. Genet. 8 (3): 215–22. doi:10.1038/sj.ejhg.5200435. PMID10780788.
Cairo S, Merla G, Urbinati F, et al. (2001). "WBSCR14, a gene mapping to the Williams--Beuren syndrome deleted region, is a new member of the Mlx transcription factor network". Hum. Mol. Genet. 10 (6): 617–27. doi:10.1093/hmg/10.6.617. PMID11230181.
Kawaguchi T, Osatomi K, Yamashita H, et al. (2002). "Mechanism for fatty acid "sparing" effect on glucose-induced transcription: regulation of carbohydrate-responsive element-binding protein by AMP-activated protein kinase". J. Biol. Chem. 277 (6): 3829–35. doi:10.1074/jbc.M107895200. PMID11724780.
Ota T, Suzuki Y, Nishikawa T, et al. (2004). "Complete sequencing and characterization of 21,243 full-length human cDNAs". Nat. Genet. 36 (1): 40–5. doi:10.1038/ng1285. PMID14702039.
Merla G, Howald C, Antonarakis SE, Reymond A (2005). "The subcellular localization of the ChoRE-binding protein, encoded by the Williams-Beuren syndrome critical region gene 14, is regulated by 14-3-3". Hum. Mol. Genet. 13 (14): 1505–14. doi:10.1093/hmg/ddh163. PMID15163635.
Li MV, Chang B, Imamura M, et al. (2006). "Glucose-dependent transcriptional regulation by an evolutionarily conserved glucose-sensing module". Diabetes. 55 (5): 1179–89. doi:10.2337/db05-0822. PMID16644671.
