Jeff DeJong, Ph.D.
B.A., Biology, University of Missouri-Columbia
Ph.D., Biochemistry, Pennsylvania State University
Postdoctoral Associate with Dr. Robert Roeder, Rockefeller University in New York
Dr. DeJong is interested in the factors and mechanism that control gene expression in eukaryotes.
In order for a gene to be expressed, a preinitiation complex composed of RNA polymerase II, general transcription factors (GTFs) TFIIA, -B, -D, -E, -F, and –H, and other factors must be assembled. The level of RNA produced is then determined by the action of gene-specific transcriptional activators or repressors and their associated cofactors.
One step in the assembly of a preinitiation complex is the recognition of core promoter DNA. This step is the primary responsibility of a family of TBP related factors including TBP, TRF1, TRF2, and TRF3. The interactions of these factors with DNA is assisted by TFIIA and ALF, and their stability is an important determinant of the rate of transcription.
Results from this lab and others have shown that distinct types of core promoter and DNA packaging factors are expressed in reproductive tissues of humans, mice, and frogs. These observations suggest there are three distinct transcription environments—somatic, spermatogenic, and oogenic—each with their own collection of core promoter factors. Further differences in the phylogenetic distribution of individual germ cell transcription factors suggest these systems are adapted to species-specific variations in reproductive physiology. Overall, the expression of transcription factor variants in reproductive tissues is believed to be important for male- or female-specific patterns of gene expression and for completion of gametogenesis. Current work in the laboratory continues to explore connections between the biochemical mechanisms of transcription, the biology of germ cells, and reproductive health.
1. Upadhyaya, A.B. and DeJong J. (2003) Expression of human TFIIA subunits in S. cerevisiae identifies regions with conserved and species-specific functions. Biochimica Biophysica Acta 1625: 88-97.
2. Han, S.Y., Xie, W., Hammes, S.R., and DeJong, J. (2003) Expression of the germ cell-specific transcription factor ALF in Xenopus oocytes compensates for translational inactivation of the somatic factor TFIIA. J. Biol. Chem. 278: 45586-45593.
3. Han, S.Y., Xie, W., Kim, S.H., Yue, L., and DeJong, J. (2004) A short core promoter drives expression of the ALF transcription factor in reproductive tissues of male and female mice. Biol. Reprod. 71: 933-941.
- Updated: February 27, 2008