Cellular localization and expression of template-activating factor I in different cell types.
Template-activating factors I (TAF-I) alpha and beta have been identified as chromatin remodeling factors from human HeLa cells. TAF-I beta corresponds to the protein encoded by the set gene, which was found in an acute undifferentiated leukemia as a fusion version with the can gene via chromosomal translocation. To determine the localization of TAF-I, we raised both polyclonal and monoclonal antibodies against TAF-I. The proteins that react to the antibodies are present not only in human cells but also in mouse, frog, insect, and yeast cells. The mouse TAF-I homologue is ubiquitous in a variety of tissue cells, including liver, kidney, spleen, lung, heart, and brain. It is of interest that the amounts of TAF-I alpha and beta vary among hemopoietic cells and some specific cell types do not contain TAF-I alpha. The level of the TAF-I proteins does not change significantly during the cell cycle progression in either HeLa cells synchronized with an excess concentration of thymidine or NIH 3T3 cells released from the serum-depleted state. TAF-I is predominantly located in nuclei, while TAF-I that is devoid of its acidic region, the region which is essential for the TAF-I activity, shows both nuclear and cytoplasmic localization. The localization of TAF-I in conjunction with the regulation of its activity is discussed.
Nagata
K
K
Department of Biomolecular Engineering, Faculty of Bioscience and Biotechnology, Tokyo Institute of Technology, Yokohama, Japan.
Saito
S
S
Okuwaki
M
M
Kawase
H
H
Furuya
A
A
Kusano
A
A
Hanai
N
N
Okuda
A
A
Kikuchi
A
A
D000595:Amino Acid Sequence; D000818:Animals; D000906:Antibodies / Q000276:immunology; D002453:Cell Cycle; D002467:Cell Nucleus / Q000378:metabolism; D002868:Chromosomal Proteins, Non-Histone; D003429:Cross Reactions; D004268:DNA-Binding Proteins / Q000032:analysis* / Q000276:immunology; D004331:Drosophila melanogaster; D005260:Female; D018922:HL-60 Cells; D006367:HeLa Cells; D056488:Histone Chaperones; D006801:Humans; D019169:Jurkat Cells; D051379:Mice; D008807:Mice, Inbred BALB C; D008969:Molecular Sequence Data; D011817:Rabbits; D014157:Transcription Factors; D014407:Tumor Cells, Cultured; D014982:Xenopus laevis
D000906:Antibodies; D002868:Chromosomal Proteins, Non-Histone; D004268:DNA-Binding Proteins; D056488:Histone Chaperones; C513473:SET protein, human; D014157:Transcription Factors