Daniel Reines, PhD
Emory University School of Medicine, Department of Biochemistry
Office: 4023 Rollins Research Center,
Emory University Department of Biochemistry
1510 Clifton Rd.
4023 Rollins Research Center
Atlanta, GA 30322
- BS, University of Rochester, Rochester, NY, 1980
- PhD, Albert Einstein College of Medicine, 1985
- Postdoc/NIH Postdoctoral Fellow, Department of Biochemistry, University of California, Berkeley, 1989
Our lab has studied many aspects of the molecular mechanisms of gene expression. Currently we are dissectiong a novel gene regulation event in yeast in which GTP regulates the expression of the enzyme that synthesizes guanine nucleotides, IMP dehydrogenase. Regulation involves a transcription start site shift that determines whether or not RNA synthesis by RNA polymerase II terminates before the open reading frame is transcribed. This termination mechanism is a specialized reaction used for small, non-coding RNAs and it employs RNA binding proteins and a helicase. Two opinion pieces describing our work and this mechanism are: B. Dichtl, 2008, Molec. Cell 31:617 & Corden, 2008, EMBO Rep. 9:1084.
Using genetic assays, we have identified mutations in the machinery that operates the terminator at the heart of this regulatory mechanism. Our attention has been drawn to the hnRNP-like protein called Nab3 which partners with Nrd1 to bind RNA polymerase, engage the nascent transcript, recruit the Sen1 helicase, and activates termination.
In addition to a classical RNA recognition motif, Nab3 possesses an essential carboxy-terminal low complexity domain. This region is proline and glutamine rich and forms amyloid polymers. A genetic and biochemical analysis has connected this termination factor to an emerging field of study of RNA binding proteins in which it has been recognized that RNA metabolism takes place in compartments formed from the self-assembly of RNA binding proteins and enzymes enriched for low complexity domains. Many proteins in this class are implicated in neurogdegenerative diseases in humans such as Alzheimer’s Disease, Huntingon’s Disease, and Lou Gehrig’s Disease (ALS). Current work focuses on why RNA binding proteins require this assembly domain and what are the signals that provoke assembly and disassembly and how polymerization is involved in function.