Oct-2 regulates CD36 gene expression via a consensus octamer, which excludes the co-activator OBF-1.
The POU domain transcription factor, Oct-2, is essential for the B cell-specific expression of CD36 in mouse B cells. In order to determine how Oct-2 mediates expression of CD36 in B cells, we cloned and analysed the mouse CD36 promoter. In contrast to the human CD36 promoter, the mouse promoter contains a consensus octamer element of the type ATGCTAAT. This octamer element can be bound by either Oct-1 or Oct-2 but requires the expression of Oct-2 to activate transcription in B cells. Mutation of the octamer element renders the CD36 promoter refractory to activation by Oct-2. Furthermore, we demonstrate that the CD36 octamer element does not support recruitment of the B cell-specific co-activator OBF-1 and that CD36 expression is unaffected in primary B cells derived from obf-1(-/-) mice. We conclude that Oct-2 activates CD36 gene expression in mouse B cells via the octamer element in the promoter. Our data also demonstrate that CD36 is the first example of an Oct-2-dependent gene whose expression in B cells is independent of OBF-1. These findings support the notion that Oct-2 regulates gene transcription by both OBF-1-dependent and -independent mechanisms.
Shore
Paul
P
School of Biological Sciences, University of Manchester, 2.205, Stopford Building, Oxford Road, Manchester M13 9PT, UK. paul.shore@man.ac.uk
Dietrich
Wendy
W
Corcoran
Lynn M
LM
D000818:Animals; D001402:B-Lymphocytes / Q000378:metabolism*; D001483:Base Sequence; D018955:CD36 Antigens / Q000096:biosynthesis / Q000235:genetics*; D002460:Cell Line; D002478:Cells, Cultured; D003001:Cloning, Molecular; D016384:Consensus Sequence; D004268:DNA-Binding Proteins / Q000378:metabolism*; D017930:Genes, Reporter; D051863:Host Cell Factor C1; D006801:Humans; D051379:Mice; D050811:Octamer Transcription Factor-1; D050813:Octamer Transcription Factor-2; D012333:RNA, Messenger / Q000096:biosynthesis; D016415:Sequence Alignment; D015534:Trans-Activators / Q000378:metabolism*; D014157:Transcription Factors / Q000378:metabolism*; D015533:Transcriptional Activation
D018955:CD36 Antigens; D004268:DNA-Binding Proteins; C497692:HCFC1 protein, human; C497693:Hcfc1 protein, mouse; D051863:Host Cell Factor C1; D050811:Octamer Transcription Factor-1; D050813:Octamer Transcription Factor-2; C091546:POU2AF1 protein, human; C494165:POU2F1 protein, human; C058435:POU2F2 protein, human; C490424:Pou2af1 protein, mouse; C494166:Pou2f1 protein, mouse; C489206:Pou2f2 protein, mouse; D012333:RNA, Messenger; D015534:Trans-Activators; D014157:Transcription Factors