The protooncogene product, PEBP2beta/CBFbeta, is mainly located in the cytoplasm and has an affinity with cytoskeletal structures.
The Pebpb2/Cbfb gene encodes the non-DNA binding beta subunit of the heterodimeric transcription factor, PEBP2/CBF, and has been implicated in a subtype of human acute myeloid leukemia, as well as being indispensable for the development of definitive hematopoiesis in the murine fetal liver. By examining a subcellular localization of the PEBP2beta/CBFbeta protein in tissue culture cells, we could reveal an additional aspect of the protein other than to be a subunit of a transcription factor. Immunoblot and immunocytochemical staining showed that PEBP2beta/CBFbeta was mostly present in the cytoplasm. This PEBP2beta/CBFbeta was free from its DNA-binding partner, the alpha subunit of PEBP2/CBF, as judged by the electrophoretic mobility shift assays. Furthermore, a significant amount of PEBP2beta/CBFbeta was retained in the cytoskeleton preparation after detergent extraction of the cells and was found by double immunofluorescence to colocalize with the F-actin on stress fibers and the vinculin in membrane processes. Thus, the present study extends PEBP2beta/CBFbeta to be a cytoskeleton-affinitive as well as nuclear protein. The implications of these results are discussed.
Tanaka
Y
Y
Department of Molecular Immunology, Institute of Development, Aging and Cancer, Tohoku University, Sendai, Japan.
Watanabe
T
T
Chiba
N
N
Niki
M
M
Kuroiwa
Y
Y
Nishihira
T
T
Satomi
S
S
Ito
Y
Y
Satake
M
M
D016475:3T3 Cells; D000199:Actins / Q000378:metabolism; D000818:Animals; D015153:Blotting, Western; D002467:Cell Nucleus / Q000378:metabolism; D002478:Cells, Cultured; D050658:Core Binding Factor beta Subunit; D003593:Cytoplasm / Q000378:metabolism*; D003599:Cytoskeleton / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000276:immunology / Q000378:metabolism*; D006801:Humans; D007150:Immunohistochemistry; D051379:Mice; D008856:Microscopy, Fluorescence; D050656:Transcription Factor AP-2; D014157:Transcription Factors / Q000276:immunology / Q000378:metabolism*; D014162:Transfection; D016596:Vinculin / Q000378:metabolism
D000199:Actins; C493692:CBFB protein, human; C493693:Cbfb protein, mouse; D050658:Core Binding Factor beta Subunit; D004268:DNA-Binding Proteins; D050656:Transcription Factor AP-2; D014157:Transcription Factors; D016596:Vinculin