TFIIIC subunits

TFIIIC subunits TFIIIC90 and TFIIICllO. The known function of TFIIIC is to initiate transcription complex formation by binding to promoter DNA and recruiting TBP-containing TFIIIB and RNA polymerase III, that directs synthesis of tRNA precursors. TFIIIC have an intrinsic HAT activity. 

In eukaryotes, the tRNA genes exist as multiple copies and are transcribed by RNA polymerase III (RNA Pol III). As in prokaryotes, several tRNAs may be transcribed together to yield a single pre-tRNA molecule that is then processed to release the mature tRNAs. The promoters of eukaryotic tRNA genes are unusual in that the transcriptional control elements are located downstream (i.e. on the 3 side) of the transcriptional start site (at position +1). In fact they lie within the gene itself. Two such elements have been identified, called the A box and B box (Fig. 3). Transcription of the tRNA genes by RNA Pol III requires transcription factor IIIC (TFIIIC) as well as TFIIIB. THIIC binds to the A and B boxes whilst TFIIIB binds upstream of the A box. TFIIIB contains three subunits, one of which is TBP (TATA binding protein), the polypeptide required by all three eukaryotic RNA polymerases. 

VI. Ordered Binding of TFIIIB Subunits to TFIIIC-DNA and Dynamic... 

Bartholomew, B., Kassavetis, G. A., and Geiduschek, E. P. (1991). Two components of Saccharomyces cerevisiae transcription factor IIIB (TFIIIB) are stereospecifically located upstream of a tRNA gene and interact with the second-largest subunit of TFIIIC. Mol. Cell. Biol. 11, 5181-5189. 

Conesa, C., Swanson, R. N., Schultz, P., Oudet, P., and Sentenac, A. (1993). On the subunit composition, stoichiometry, and phosphorylation of the yeast transcription factor TFIIIC/tau. J. Biol. Chem. 268, 18047-18052. 

Deprez, E., Arrebola, R., Conesa, C., and Sentenac, A. (1999). A subunit of yeast TFIIIC participates in the recruitment of TATA-binding protein. Mol. Cell. Biol. 19, 8042-8051. 

Dumay, H., Rubbi, L., Sentenac, A., and Marek, C. (1999). Interaction between yeast RNA polymerase III and transcription factor TFIIIC via ABClOalpha and taul31 subunits. / Biol. Chem. 274, 33462-33468. 

Hsieh, Y. J., Kundu, T. K., Wang, Z., Kovelman, R., and Roeder, R. G. (1999a). The TFIIIG90 subunit of TFIIIC interacts with multiple components of the RNA polymerase III machinery and contains a histone-specific acetyltransferase activity. Mol. Cell. Biol. 19, 7697-7704. 

Huang, Y., Hamada, M., and Maraia, R. J. (2000). Isolation and cloning of four subunits of a fission yeast TFIIIC complex that includes an ortholog of the human regulatory protein TFIIICbeta. J. Biol. Chem. 275, 31480—31487. 

Lefebvre, O., Ruth, J., and Sentenac, A. (1994). A mutation in the largest subunit of yeast TFIIIC affects tRNA and 5 S RNA synthesis. Identification of two classes of suppressors. / Biol. Chem. 269, 23374—23381. 

Marek, C., Lefebvre, O., Carles, C., Riva, M., Chaussivert, N., Ruet, A., and Sentenac, A. (1993). The TFIIIB assembling subunit of yeast transcription factor TFIIIC has both tetratricopoptide repeats and basic helix loop-helix motifs. Proc. Natl. Acad. Sci. USA 90, 4027-4031. 

Moir, R. D., Puglia, K. C., and Willis, I. M. (2002b). Autoinhibition of TFIIIB70 binding by the tetratricopeptide repeat containing subunit of TFIIIC. J. Biol. Chem. 277, 694-701. 

Rameau, G., Puglia, K., Crowe, A., Sethy, I., and Willis, I. (1994). A mutation in the second largest subunit of TFIIIC increases a rate limiting step in transcription by RNA polymerase III. Mol. Cell. Biol. 14, 822-830. 

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