Prf, a novel Ets family protein that binds to the PU.1 binding motif, is specifically expressed in restricted stages of B cell development.
During the development of lymphocytes, expression of the Ig genes is strictly regulated in a tissue-specific manner and in a time-ordered fashion. We have previously shown that the PU.1 binding motif in the Igkappa 3' enhancer (kappaE3') and a novel Ets family protein other than PU.1 may be possibly involved in the control of V(kappa)-J(kappa) joining. In the attempt to isolate the novel Ets family protein, we have screened cDNA libraries with the yeast one-hybrid method and identified a new PU.1-related factor, Prf. This novel Ets family protein is shown to interact with the PU.1 binding sequences in various promoters and enhancers, including kappaE3'. It was found that expression of the prf gene is predominant in the B-lineage cells, with the exception of immature B cells. Since Prf does not exhibit functions of transcriptional activity, this novel protein may act as an antagonist against other Ets family proteins, e.g. PU.1 and Spi-B. Possible roles of Prf with respect to the B cell differentiation are discussed.
Hashimoto
S
S
Department of Biophysics and Biochemistry, Graduate School of Science, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
Nishizumi
H
H
Hayashi
R
R
Tsuboi
A
A
Nagawa
F
F
Takemori
T
T
Sakano
H
H
D000595:Amino Acid Sequence; D000818:Animals; D001402:B-Lymphocytes / Q000737:chemistry* / Q000166:cytology; D001483:Base Sequence; D001854:Bone Marrow Cells / Q000378:metabolism; D002454:Cell Differentiation / Q000187:drug effects; D018076:DNA, Complementary / Q000235:genetics; D004268:DNA-Binding Proteins / Q000235:genetics; D004742:Enhancer Elements, Genetic / Q000235:genetics; D006801:Humans; D051379:Mice; D008810:Mice, Inbred C57BL; D008969:Molecular Sequence Data; D016366:Open Reading Frames; D016133:Polymerase Chain Reaction; D011518:Proto-Oncogene Proteins / Q000737:chemistry*; D050783:Proto-Oncogene Proteins c-ets; D012333:RNA, Messenger / Q000032:analysis; D013154:Spleen / Q000166:cytology; D013950:Thymus Gland / Q000166:cytology; D015534:Trans-Activators / Q000737:chemistry*; D014157:Transcription Factors / Q000737:chemistry* / Q000235:genetics; D000099232:Proto-Oncogene Protein Spi-1
D018076:DNA, Complementary; D004268:DNA-Binding Proteins; D011518:Proto-Oncogene Proteins; D050783:Proto-Oncogene Proteins c-ets; D012333:RNA, Messenger; D015534:Trans-Activators; D014157:Transcription Factors; D000099232:Proto-Oncogene Protein Spi-1; C076877:SPIB protein, human