The epidermal growth factor receptor (EGFR) plays a critical role in normal growth and its overexpression is associated with several types of cancer. To learn more about regulation of the expression of this important receptor, we investigated the role of the TAFII250 subunit of transcription factor IID in the transcription of the EGFR gene. The EGFR gene has a TATA-less promoter and TAFII250 has previously been shown to have an important regulatory role in such promoters. The study was performed in the ts13 hamster cell line which has a temperature-sensitive mutation in the CCG1 gene that encodes TAFII250. At the nonpermissive temperature, the transcription of a few cell cycle-dependent genes is depressed in ts13 cells while global RNA synthesis is unaffected. Using this model system, we found that EGFR promoter-driven luciferase expression in transiently transfected ts13 cells decreased 8, 25, and 50-fold after 12, 24, and 48 hours, respectively, at the nonpermissive temperature. The decrease was partially rescued by cotransfection with the wild-type CCG1 gene. The expression of endogenous EGFR also appeared to be regulated by TAFII250the maximum binding capacity of ts13 cells for 125I-labeled EGF decreased approximately twofold when incubated for 2 days at the nonpermissive temperature. Placing these studies in the context of the current understanding of the TFIID transcription complex, we speculate that selective stimulation of EGFR gene transcription may be mediated by TAFII250 interaction with enhancer-bound activators and the basal transcription machinery. J. Cell. Physiol. 176:642647,1998. © 1998 Wiley-Liss, Inc.