Requirement for TAF_II250 Acetyltransferase Activity in Cell Cycle Progression

Abstract

The TATA-binding protein (TBP)-associated factor TAF_II250 is the largest component of the basal transcription factor IID (TFIID). A missense mutation that maps to the acetyltransferase domain of TAF_II250 induces the temperature-sensitive (ts) mutant hamster cell lines ts13 and tsBN462 to arrest in late G₁. At the nonpermissive temperature (39.5°C), transcription from only a subset of protein encoding genes, including the G₁ cyclins, is dramatically reduced in the mutant cells. Here we demonstrate that the ability of the ts13 allele of TAF_II250 to acetylate histones in vitro is temperature sensitive suggesting that this enzymatic activity is compromised at 39.5°C in the mutant cells. Mutagenesis of a putative acetyl coenzyme A binding site produced a TAF_II250 protein that displayed significantly reduced histone acetyltransferase activity but retained TBP and TAF_II150 binding. Expression of this mutant in ts13 cells was unable to complement the cell cycle arrest or transcriptional defect observed at 39.5°C. These data suggest that TAF_II250 acetyltransferase activity is required for cell cycle progression and regulates the expression of essential proliferative control genes.

View correction statement:

Requirement for TAFII250 Acetyltransferase Activity in Cell Cycle Progression

ACKNOWLEDGMENTS

We are indebted to K. White for preparation of His-hTBP bacterial cell extracts. We thank R. Tjian for providing the anti-HA ascites fluid, P. Verrijzer for the His-hTBP plasmid construct, R. Moon for the CS2+MT expression vector, and N. Davies for advice on in vitro HAT assays. We especially thank members of the Wang lab for valuable discussions and G. S. McKnight for critical reading of the manuscript.

E. L. Dunphy was supported in part by Public Health Service National Research Service Award T32 GM07270 from the National Institute of General Medical Sciences. This work was supported by research project grant RPG-98-201-CCG from the American Cancer Society and by startup funds from the Howard Hughes Medical Institute.