Cloning of a lymphoid-specific cDNA encoding a protein binding the regulatory octamer DNA motif.
An octamer DNA sequence plays a critical role in directing transcription of immunoglobulin genes in B lymphocytes. A new technique of direct binding of radioactive DNA was used to screen a complementary DNA expression library from the BJAB cell line in lambda gt11 phage to derive molecular cDNA clones representing a putative B lymphocyte-specific octamer binding protein. The plaques were screened with DNA containing four copies of the octamer sequence and positive phage recombinants were identified. The fusion protein produced on inducing a lysogen of one phage bound to a monomeric octamer probe. The cDNA insert from this phage hybridized to messenger RNA found in B lymphocytes, but not in most other cells. Thus, this cDNA derives from a gene (oct-2) that specifies an octamer binding protein expressed preferentially in B lymphocytes, proving that, for at least one gene, a cell-specific transcription factor exists and its amount is controlled through messenger RNA availability.
Staudt
L M
LM
Whitehead Institute for Biomedical Research, Cambridge, MA 02142.
Clerc
R G
RG
Singh
H
H
LeBowitz
J H
JH
Sharp
P A
PA
Baltimore
D
D
D003001:Cloning, Molecular; D004247:DNA / Q000235:genetics; D004268:DNA-Binding Proteins / Q000502:physiology*; D005786:Gene Expression Regulation; D005796:Genes; D006801:Humans; D008214:Lymphocytes / Q000502:physiology*; D012045:Regulatory Sequences, Nucleic Acid; D014157:Transcription Factors / Q000502:physiology*
D004268:DNA-Binding Proteins; D014157:Transcription Factors; D004247:DNA