Two promoters direct expression of the murine Spi-B gene, an Ets family transcription factor.
Spi-B and PU.1 (Spi-1) comprise the most divergent subfamily of the Ets transcription factor family. Spi-B and PU.1 bind to similar DNA sequences, and can activate the same B-cell and myeloid promoters in vitro. However, PU.1 knockout mice demonstrate defective hematopoietic development of multiple hematopoietic lineages, indicating that Spi-B was not able to compensate for loss of PU.1. One explanation for these results is that, in contrast to PU.1, which is expressed in myeloid and B-cell lines, Spi-B expression is restricted to B-cells. In order to begin to understand the control of regulation of the Spi-B gene, murine Spi-B cDNA and genomic clones were isolated. The exon/intron organization and transcriptional start sites were determined; two major transcriptional start sites were detected. The two Spi-B promoters were isolated and characterized, and displayed differential activity in B-cell lines matching that of the endogenous gene. Further study of the two Spi-B promoters will provide insight into the molecular events regulating the tissue-specific and developmental stage-specific expression of Spi-B in B-cells.
Chen
H M
HM
Department of Medicine, Beth Israel Deaconess Medical Center, Boston, MA 02215, USA.
Gonzalez
D A
DA
Radomska
H S
HS
Voso
M T
MT
Sun
Z
Z
Zhang
P
P
Zhang
D E
DE
Tenen
D G
DG
D000595:Amino Acid Sequence; D000818:Animals; D001402:B-Lymphocytes / Q000378:metabolism; D001483:Base Sequence; D002460:Cell Line; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000302:isolation & purification; D004268:DNA-Binding Proteins / Q000235:genetics*; D005786:Gene Expression Regulation; D006367:HeLa Cells; D006801:Humans; D051379:Mice; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic; D050783:Proto-Oncogene Proteins c-ets / Q000235:genetics*; D012333:RNA, Messenger / Q000378:metabolism; D015183:Restriction Mapping; D017386:Sequence Homology, Amino Acid; D014157:Transcription Factors / Q000235:genetics*; D014158:Transcription, Genetic; D014407:Tumor Cells, Cultured
D018076:DNA, Complementary; D004268:DNA-Binding Proteins; D050783:Proto-Oncogene Proteins c-ets; D012333:RNA, Messenger; C514177:Spi-B protein, mouse; D014157:Transcription Factors; C076877:SPIB protein, human