JAZF1 is a 27 kDa nuclear protein containing two putative zinc finger motifs that is associated with diabetes mellitus and prostate cancer according to genomewide association studies; however, little is known about the function of this gene in regulating metabolism. Recent evidence indicates that JAZF1 transcription factors bind to the nuclear orphan receptor TR4 and act as a strong repressor. This receptor regulates PEPCK, the key enzyme in gluconeogenesis, at the transcriptional level. Excess PEPCK expression in mice causes hyperglycemia, hyperinsulinemia, and increased glucose turnover. Therefore, we hypothesized that ectopic expression of Jazf1 may lead to abnormal expression of PEPCK that allow for the metabolic disorder. To elucidate its role in metabolism, we fed the mice with high- or normal- fat diet up to 18 weeks. In the liver tissue of mice, Jazf1 overexpression led to a substantial reduction in the expression of PEPCK. In Jazf1 overexpression mice, weight gain was found to be significantly decreased and increment of blood glucose level also decreased. Our data suggest that Jazf1 plays a critical role in the regulation of energy and lipid homeostasis, and promotes the development of metabolic disorder. Jazf1 may provide a new therapeutic target in the management of obesity, diabetes, and liver steatosis.

The C3HC4 zinc RING finger proteins seem to be a family of protein-protein interactions. Little is information regarding the role of the C3HC4 zinc RING finger proteins in rice plant. We have attempted to assess their genome localization, phylogenetic relationship and expression patterns of members via in silico analysis as well as semi-quantitative RT-PCR. A total of 132 genes encoding C3HC4 zinc RING finger proteins appear to be distributed over 12 rice chromosomes, reflecting evolutionary dynamics of the rice genome, e.g. whole genome duplication and tandem duplications. A genome-wide dataset including 155 gene expression omnibus sample (GSM) plates evidenced a high degree of functional specialization of the rice C3HC4 zinc RING finger proteins, especially during developmental stages and against abiotic stresses. We have retrieved co-expression genes with each of the rice C3HC4 zinc RING finger proteins, probably providing some clues on specialized functions of individual genes. Expression patterns of 13 co-expression genes with one gene encoding C3HC4 zinc RING finger protein (Os04g51400) against salt and dehydration stresses were evaluated in crown tissues and leaf tissues, evidencing highly similar patterns among members. These findings might provide clues to shed further light on comprehensive functions of C3HC4 zinc RING finger proteins.