BACKGROUND: The tsBN462 temperature-sensitive mutant hamster cell line exhibits cell cycle arrest and apoptosis at the restrictive temperature of 39.5 degrees C, due to a point mutation in the CCG1/TAFII250 gene, which encodes a component of the general transcription factor TFIID. RESULTS: We now report that CCG1/TAFII250 persisted as a complex with TBP and associated proteins (TAFs) in tsBN462 cells at the restrictive temperature. FACScan analysis revealed that the tsBN462 mutation resulted in a failure to progress out of G0 into G1. Using two-dimensional gel electrophoresis we observed a decrease in the synthesis of several proteins, starting in the middle of the G1 phase, becoming very pronounced during late G1. The expression of the immediate early genes c-fos, c-jun and c-myc was normally induced by serum treatment of quiescent cells at the restrictive temperature, whereas expression of cyclins A, D1 and D3 was reduced. Expression of the cyclin-dependent kinase (CDK) inhibitor proteins p21 and p27 was enhanced. Consistent with the decreased cyclin D and increased p21/p27 expression, we found that phosphorylation of Rb was decreased at 39.5 degrees C. Cyclin A-, E- and Cdk2-associated histone H1 kinase activity was reduced concomitantly with the increase in p21 protein. CONCLUSION: Decreased cyclin/Cdk kinase activity and decreased Rb phosphorylation are possible causes of G1 cell cycle arrest in tsBN462 cells at the restrictive temperature.

This article has been cited by other articles:

				T. L. Hilton, Y. Li, E. L. Dunphy, and E. H. Wang TAF1 Histone Acetyltransferase Activity in Sp1 Activation of the Cyclin D1 Promoter Mol. Cell. Biol., May 15, 2005; 25(10): 4321 - 4332. [Abstract] [Full Text] [PDF]

				A. M. Buchmann, J. R. Skaar, and J. A. DeCaprio Activation of a DNA Damage Checkpoint Response in a TAF1-Defective Cell Line Mol. Cell. Biol., June 15, 2004; 24(12): 5332 - 5339. [Abstract] [Full Text] [PDF]

				S. M. Dehm, T. L. Hilton, E. H. Wang, and K. Bonham SRC Proximal and Core Promoter Elements Dictate TAF1 Dependence and Transcriptional Repression by Histone Deacetylase Inhibitors Mol. Cell. Biol., March 15, 2004; 24(6): 2296 - 2307. [Abstract] [Full Text] [PDF]

				Y. Wang, T. Sekiguchi, E. Noguchi, and T. Nishimoto A Hamster Temperature-Sensitive Alanyl-tRNA Synthetase Mutant Causes Degradation of Cell-Cycle Related Proteins and Apoptosis J. Biochem., January 1, 2004; 135(1): 7 - 16. [Abstract] [Full Text] [PDF]

				J. Fukumura, E. Noguchi, T. Sekiguchi, and T. Nishimoto A Temperature-Sensitive Mutant of the Mammalian RNA Helicase, DEAD-BOX X Isoform, DBX, Defective in the Transition from G1 to S Phase J. Biochem., July 1, 2003; 134(1): 71 - 82. [Abstract] [Full Text] [PDF]

				T. L. Hilton and E. H. Wang Transcription Factor IID Recruitment and Sp1 Activation. DUAL FUNCTION OF TAF1 IN CYCLIN D1 TRANSCRIPTION J. Biol. Chem., April 4, 2003; 278(15): 12992 - 13002. [Abstract] [Full Text] [PDF]

				C. Wasylyk and B. Wasylyk Defect in the p53-Mdm2 Autoregulatory Loop Resulting from Inactivation of TAFII250 in Cell Cycle Mutant tsBN462 Cells Mol. Cell. Biol., August 1, 2000; 20(15): 5554 - 5570. [Abstract] [Full Text]

				Y. Tsukihashi, T. Miyake, M. Kawaichi, and T. Kokubo Impaired Core Promoter Recognition Caused by Novel Yeast TAF145 Mutations Can Be Restored by Creating a Canonical TATA Element within the Promoter Region of the TUB2 Gene Mol. Cell. Biol., April 1, 2000; 20(7): 2385 - 2399. [Abstract] [Full Text]

				E. L. Dunphy, T. Johnson, S. S. Auerbach, and E. H. Wang Requirement for TAFII250 Acetyltransferase Activity in Cell Cycle Progression Mol. Cell. Biol., February 15, 2000; 20(4): 1134 - 1139. [Abstract] [Full Text]

				F. Kashanchi, E. T. Agbottah, C. A. Pise-Masison, R. Mahieux, J. Duvall, A. Kumar, and J. N. Brady Cell Cycle-Regulated Transcription by the Human Immunodeficiency Virus Type 1 Tat Transactivator J. Virol., January 1, 2000; 74(2): 652 - 660. [Abstract] [Full Text]

				J. Martin, R. Halenbeck, and J. Kaufmann Human Transcription Factor hTAFII150 (CIF150) Is Involved in Transcriptional Regulation of Cell Cycle Progression Mol. Cell. Biol., August 1, 1999; 19(8): 5548 - 5556. [Abstract] [Full Text] [PDF]

				D. M. Lukac and J. C. Alwine Effects of Human Cytomegalovirus Major Immediate-Early Proteins in Controlling the Cell Cycle and Inhibiting Apoptosis: Studies with ts13 Cells J. Virol., April 1, 1999; 73(4): 2825 - 2831. [Abstract] [Full Text]

				N. Saadane, L. Alpert, and L. E. Chalifour TAFII250, Egr-1, and D-type cyclin expression in mice and neonatal rat cardiomyocytes treated with doxorubicin Am J Physiol Heart Circ Physiol, March 1, 1999; 276(3): H803 - H814. [Abstract] [Full Text] [PDF]

				E. H. Wang, S. Zou, and R. Tjian TAFII250-dependent transcription of cyclin A is directed by ATF activator proteins Genes & Dev., October 15, 1997; 11(20): 2658 - 2669. [Abstract] [Full Text] [PDF]