title: Identification of a novel gene, MSAG, regulated by high levels of glucose and insulin.
abstract: Identification and characterization of novel genes involved in derangement of metabolisms of glucose and triglycerides are important in understanding the development of metabolic syndrome (MS) and atherosclerosis. Model rats with certain phenotypes of MS were fed a high-carbohydrate diet. The rat hepatic subtracted cDNA libraries were constructed and screened. A novel cDNA of full length was identified by screening of a human hepatic cDNA library with a mixture of probes of the differentially expressed fragments from the rat hepatic subtracted cDNA libraries. The corresponding gene of the cDNA was temporarily named metabolic syndrome-associated gene (MSAG). The predicted protein encoded by MSAG contains 110 amino acids and has a theoretical molecular weight of 11667.04 and an isoelectric point of 4.91. Compared with the housekeeping gene of beta-actin, MSAG had low transcription activity. However, the mRNA level of MSAG in HepG2 cells, a human hepatoma cell line, was significantly increased by glucose and decreased by insulin concentrations higher than physiological levels. These results suggest that MSAG may be involved in the metabolism and/or its regulation of glucose, the functioning of insulin under non-physiological conditions, and further in the development of metabolic syndrome.
authors.affiliation: Department of Biochemistry and Molecular Biology, State Key Laboratory of Oral Diseases, West China Medical Center, Sichuan University, Chengdu, 610041, PR China.
authors.forename: Xiao Yan
authors.initials: XY
authors.lastname: Cui
authors.forename: Jin Xin
authors.initials: JX
authors.lastname: Chen
authors.forename: Bing Wen
authors.initials: BW
authors.lastname: Liu
authors.forename: Li Ying
authors.initials: LY
authors.lastname: Xiao
authors.forename: Ding Zhi
authors.initials: DZ
authors.lastname: Fang
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D018797:Cell Cycle Proteins; D045744:Cell Line, Tumor; D005786:Gene Expression Regulation; D005947:Glucose / Q000494:pharmacology*; D006801:Humans; D007328:Insulin / Q000494:pharmacology*; D008297:Male; D008969:Molecular Sequence Data; D011506:Proteins / Q000235:genetics* / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid
chemical_list: C539689:ANAPC16 protein, human; D018797:Cell Cycle Proteins; D007328:Insulin; D011506:Proteins; D005947:Glucose