3788 Nucleic Acids Research, Vol. 20, No. 14
Q'D) 1992 Oxford University Press
Conserved structural motifs within the N-terminal domain of TFIIDr from Xenopus, mouse and human Shigeru Hashimoto1, Hisakazu Fujital, Satoshi Hasegawa', Robert G.Roeder1 and Masami Horikoshi 2, * 'Laboratory of Biochemistry and Molecular Biology, The Rockefeller University, New York, NY 10021, USA and 2Institute of Applied Microbiology, University of Tokyo, Bunkyo-ku, Tokyo 113, Japan Submitted May 20, 1992 The TATA box-binding protein TFIIDr is a key component of native TFLD and binds to the TATA box. Other general initiation factors and RNA polymerase II recognize the TFIIDr-TATA box complex and assemble in a defined order (1). In principle, any of the individual steps (and corresponding factors) in preinitiation complex formation are potential points of regulation. In fact, earlier studies with partially purified human TFIID showed that it is a target for various transcriptional activators and thus plays a central role in the regulation of transcription (2, 3). Success in the cloning of a gene for yeast TFIIDr led to the isolation of TFIIDT cDNAs from several other eukaryotes (reviewed in 4, 5). It was found that the region encompassing the C-terminal 180 amino acids is highly conserved between species (5) and is both necessary and sufficient for basal function of TFIIDr (6, 7). However, the N-terminal region varies considerably in length and in primary structure in different species (5). Recent in vivo data suggest that the N-terminal region of TFIDrT is not important for normal cell growth, at least in yeast (reviewed in 4). In higher eukaryotes, the N-terminal region of TFIIDr includes a number of potentially interesting structural motifs. However, their exact roles in transcriptional regulation are not clear as direct functional tests in various reconstituted systems have shown variable requirements of the N-terminal region for different activators (8-11). Thus it could be informative to compare the primary structures of the N-terminal region of TFIIDT between more closely related species. In this paper, we describe the isolation of a TFIIDr cDNA from Xenopus laevis (Figure 1). In addition to a perfect conservation of the C-terminal core domain, most of the structural motifs found in the N-terminal regions of human (5) and mouse TFIIDr (12) are also highly conserved in Xenopus TFIIDr. In particular, the glutamine residues in the glutamine rich region (amino acid residues 62-84) are perfectly conserved even though the amino acids between each of the glutamine residues are not well conserved. Furthermore, the serinethreonine-proline rich regions located adjacent to the glutamine rich and glutamine repeat regions are also highly conserved. However, the number of glutamines in the glutamine repeat region is highly variable between species (34/38 in human, 13 in mouse and 4 in Xenopus). The development of activatorresponsive TFIIDr-dependent systems to detect functional differences between wild type and N-terminal mutants of TFIIDr is underway.
ACKNOWLEDGMENTS We thank Dr Robert Kovelman for a critical reading of the manuscript and Drs Jerry Thomsen and Doug A.Melton for the Xenopus laevis cDNA library. M.H. was an Alexandrine and Alexander L.Sinsheimer Scholar. This study was supported by grants from the National Institutes of Health to M.H. and R.G.R. and by the Pew Trusts to The Rockefeller University.
REFERENCES 1. Roeder,R.G. (1991) Trends Biochem. Sci. 16, 402-408. 2. Horikoshi,M., Carey,M.F., Kakidani,H. and Roeder,R.G. (1988) Cell 54, 665-669. 3. Horikoshi,M., Hai,T., Lin,Y.-S., Green,M.R. and Roeder,R.G. (1988) Cell 54, 1033-1042. 4. Greenblatt,J. (1991) Cell 66, 1067-1070. 5. Hoffmann,A., Sinn,E., Yamamoto,T., Wang,J., Roy,A., Horikoshi,M. and Roeder,R.G. (1990) Nature 346, 387-390. 6. Horikoshi,M., Yamamoto,T., Ohkuma,Y., Weil,P.A. and Roeder,R.G. (1990) Cell 61, 1171-1178. 7. Yamamoto,T., Horikoshi,M., Wang,J., Hasegawa,S., Weil,P.A. and Roeder,R.G. (1992) Proc. Natl. Acad. Sci. USA 89, 2844-2848. 8. Peterson,M.G., Tanese,N., Pugh,B.F. and Tjian,R. (1990) Science 248, 1625-1630. 9. Kao,C.C., Lieberman,P.M., Schmidt,M.C., Zhou,Q., Pei,R. and Berk,A.J. (1990) Science 248, 1646-1649. 10. Meisterernst,M., Horikoshi,M. and Roeder,R.G. (1990) Proc. Natl. Acad. Sci. USA 87, 9153-9157.
Kelleher,R.J.,11I, Flanagan,P.M., Chasman,D.I., Ponticelli,A.S., Struhl,K. and Kornberg,R.D. (1992) Genes & Develop. 6, 296-303. 12. Tamura,T., Sumita,K., Fujino,I., Aoyama,A., Horikoshi,M., Hoffmann,A., Roeder,R.G., Muramatsu,M. and Mikoshiba,K. (1991) Nucleic Acids Res. 19, 3861-3865. 11.
H: M: X:
H: SQQATQGTSGQAPQLFHSQTLTTAPLPGTTPLYPSPMTPMTPITPATPASES 154 M: A T P 135 X: L GN T P N I S 116
1. Comparison of amino acid sequences in the N-terminal region of TFHID from Xenopus (X), mouse (M) and human (H). Residues in mouse or Xenopus TFIIDT which are identical to corresponding residues in human TFIIDr ones are shown as blanks. Numbers indicate positions from the N-terminus of each TFIIDr. Fire
*To whom correspondence should be addressed at: Laboratory of Biochemistry and Molecular Biology, The Rockefeller University, New York, NY 10021, USA