Analysis of cis-acting elements present in the CD20/B1 antigen promoter.
A genomic clone spanning a large portion of the 5' untranscribed region of the CD20 gene was isolated. Deletion analysis of subcloned fragments identified several regulatory elements. A major positive cis-acting element was localized between base pairs -290/-186. A second positive regulatory element was localized between -454/-280 and negative regulatory elements were present in the region between bp -828/-454. The sequence -280/-186 conferred B cell-specific expression on a heterologous, TATA box containing c-fos promoter. Electrophoretic mobility shift assays with overlapping oligonucleotide probes spanning -280/-186 revealed that a 25-bp probe (-225/-201) bound a nuclear protein present in B cell lines expressing the CD20/B1 antigen but not in Jurkat (T cell), U937 (promonocytic), U251 (glioma), or HeLa cells. To confirm the functional significance of this sequence, a trimer of this region was subcloned into the c-fos promoter containing CAT plasmid. Expression was observed only in BJA-B and HS-Sultan cells but not in CD20/B1- cell lines. This sequence element is also important in phorbol ester-induced CD20 expression in the pre-B cell line BP-697. These results partially characterize several regulatory elements present in the CD20 promoter that are likely important in the B cell-specific expression of the CD20 gene.
Rieckmann
P
P
Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892.
Wilson
G L
GL
Thevenin
C
C
Hong
J X
JX
Kehrl
J H
JH
D015703:Antigens, CD / Q000235:genetics*; D018951:Antigens, CD20; D000944:Antigens, Differentiation, B-Lymphocyte / Q000235:genetics*; D001402:B-Lymphocytes / Q000502:physiology*; D004252:DNA Mutational Analysis; D004268:DNA-Binding Proteins / Q000502:physiology; D004742:Enhancer Elements, Genetic; D005786:Gene Expression Regulation / Q000187:drug effects; D005796:Genes; D006801:Humans; D009841:Oligonucleotides / Q000737:chemistry; D011401:Promoter Regions, Genetic; D015183:Restriction Mapping; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology
D015703:Antigens, CD; D018951:Antigens, CD20; D000944:Antigens, Differentiation, B-Lymphocyte; D004268:DNA-Binding Proteins; D009841:Oligonucleotides; D013755:Tetradecanoylphorbol Acetate