Cell Biology

Faculty and Research Interests

Dmitry Temiakov, PhD

Assistant Professor
Science Center 206B
856 566-6327
temiakdm@umdnj.edu

Education

Institute for Genetics, Russian Academy of Science, Moscow
PhD (Molecular Biology) , 1996

Russian Chemical University by Mendeleev, Moscow
MS (Biotechnology) , 1993

Research Interests

The focus of our research is to understand the molecular mechanisms of transcription and its regulation in human mitochondria. Mitochondria, the power plants of human cells, maintain their own genomes that encode proteins involved in oxidative phosphorylation. Expression of these genes is driven by a unique transcription system that involves a nuclear-encoded single subunit T7 phage-like mitochondrial RNAP polymerase (RNAP) that requires two auxiliary factors – transcription factor A (TFA) and transcription factor B2 (TFB2) for efficient initiation. Transcription in mitochondria is likely to be highly regulated, as a number of factors that affect transcription, such as MRPL12 and MTERF1-3, were recently discovered. We use an array of genetic, molecular biology, biochemical and biophysical methods to study interactions of the mitochondrial RNAP with transcription factors, and mechanisms that affect promoter recognition and fidelity. In the past, we were able to obtain crystals of other RNAPs in complex with RNA and DNA – elongation complexes of T7 RNAP and T.thermophilus RNAP. We are now working on crystallization of the human mitochondrial transcription initiation complex.

Recent Publications

1. Temiakov D., Mentesana P.E., Ma K., Mustaev A., Borukhov S. & McAllister W. T. (2000). The specificity loop of T7 RNA polymerase interacts first with the promoter and then with the elongating transcript, suggesting a mechanism for promoter clearance. Proc. Nat Acad. Sci U.S.A. 97:14709-14.
   
2. Tahirov T.H., Temiakov D., Anikin M., Patlan V., McAllister W. T., Vassylyev D.G. & Yokoyama S. (2002). Structure of a T7 RNA polymerase elongation complex at 2.9 A resolution. Nature 420:43-50.
3. Temiakov D., Patlan V, Anikin M, McAllister W.T., Yokoyama S., Vassylyev D.G. (2004) Structural basis for substrate by T7 RNA polymerase. Cell, 116(3):381-91.
   
4. Temiakov D., Zenkin N., Vassylyeva, M., Perederina A., Tahirov T., Kashkina, E., Savkina M., Zorov S., Nikiforov V., Igarashi N., Matsugaki N., Wakatsuki S., Severinov K., Vassylyev D.G. Structural basis of transcription inhibition by antibiotic streptolydigin. Mol Cell 2005 19 (5):655-666.
5. Ma K., Temiakov D., Anikin M., McAllister WT. Probing conformational changes in T7 RNA polymerase during initiation and termination by using engineered disulfide linkages. Proc Natl Acad Sci U S A. 2005 Dec 6;102(49):17612-17617
6. Kashkina E, Anikin M, Tahirov TH, Kochetkov SN, Vassylyev DG, Temiakov D. Elongation complexes of Thermus thermophilus RNA polymerase that possess distinct translocation conformations. Nucleic Acids Res. 2006;34(14):4036-45. Epub 2006 Aug 16.
7. Kashkina E, Anikin M, Brueckner F, Pomerantz RT, McAllister WT, Cramer P, Temiakov D. Template misalignment in multisubunit RNA polymerases and transcription fidelity. Mol Cell. 2006 Oct 20;24(2):257-66
8. Pomerantz RT, Temiakov D, Anikin M, Vassylyev DG, McAllister WT. A Mechanism of Nucleotide Misincorporation during Transcription due to Template Strand Misalignment. Mol Cell. 2006 Oct 20;24(2):245-255
9. Kashkina E, Anikin M, Brueckner F, Lehmann E., Kochetkov S, McAllister WT, Cramer P, Temiakov D. Multisubunit RNA polymerases melt only a single DNA base pair downstream of the active cite. JBC. 2007 May 24;Vol 282