Identification of CD36 as the first gene dependent on the B-cell differentiation factor Oct-2.
The Oct-2 transcription factor is expressed predominantly in B lymphocytes and has been shown previously to be important for the terminal phase of B-cell differentiation in mice. A number of genes specifically expressed in B cells contain Oct-2-binding sites in their regulatory regions. However, the analysis of expression levels of these genes in Oct-2-deficient B cells revealed that they were unaffected. Hence, there were no genes known that critically depend on Oct-2 for their expression. To understand the molecular basis for the Oct-2 effect on B-cell development, we searched for Oct-2 target genes by subtractive cDNA cloning. We show here that expression of the murine CD36 gene in B cells and macrophages requires a functional Oct-2 protein. Nuclear run-on experiments demonstrate that this gene is regulated transcriptionally by Oct-2. Moreover, CD36 levels correlated with the levels of Oct-2 expression in several mouse B-cell and macrophage cell lines. Finally, compared to wild-type and heterozygous mice, CD36 mRNA levels were markedly reduced in spleens and B-cell-enriched splenocyte fractions from oct-2-/- mice. The data identify CD36 as the first target gene critically dependent on Oct-2 for its expression. Because CD36 expression is also dependent on Oct-2 in vivo, it is a candidate gene through which Oct-2 could affect B-cell differentiation.
König
H
H
Zentrum für Molekulare Biologie Heidelberg, Germany.
Pfisterer
P
P
Corcoran
L M
LM
Wirth
T
T
D000818:Animals; D015703:Antigens, CD / Q000096:biosynthesis*; D001402:B-Lymphocytes / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D001483:Base Sequence; D018955:CD36 Antigens; D002460:Cell Line; D017931:DNA Primers; D004268:DNA-Binding Proteins / Q000378:metabolism*; D004958:Estradiol / Q000494:pharmacology; D005786:Gene Expression Regulation; D008264:Macrophages / Q000378:metabolism; D051379:Mice; D008817:Mice, Mutant Strains; D008969:Molecular Sequence Data; D050813:Octamer Transcription Factor-2; D012333:RNA, Messenger / Q000302:isolation & purification / Q000378:metabolism; D014157:Transcription Factors / Q000378:metabolism; D014158:Transcription, Genetic
D015703:Antigens, CD; D018955:CD36 Antigens; D017931:DNA Primers; D004268:DNA-Binding Proteins; D050813:Octamer Transcription Factor-2; C489206:Pou2f2 protein, mouse; D012333:RNA, Messenger; D014157:Transcription Factors; D004958:Estradiol