Transcriptional regulation of the mouse alpha A-crystallin gene: activation dependent on a cyclic AMP-responsive element (DE1/CRE) and a Pax-6-binding site.
Two cis-acting promoter elements (-108 to -100 and -49 to -33) of the mouse alpha A-crystallin gene, which is highly expressed in the ocular lens, were studied. Here we show that DE1 (-108 to -100; 5'TGACGGTG3'), which resembles the consensus cyclic AMP (cAMP)-responsive element sequence (CRE; 5'TGACGT[A/C][A/G]3'), behaves like a functional CRE site. Transfection experiments and electrophoretic mobility shift assays (EMSAs) using site-specific mutations correlated a loss of function with deviations from the CRE consensus sequence. Results of EMSAs in the presence of antisera against CREB, delta CREB, and CREM were consistent with the binding of CREB-like proteins to the DE1 sequence. Stimulation of alpha A-crystallin promoter activity via 8-bromo-cAMP, forskolin, or human T-cell leukemia virus type I Tax1 in transfections and reduction of activity of this site in cell-free transcription tests by competition with the somatostatin CRE supported the idea that DE1 is a functional CRE. Finally, Pax-6, a member of the paired-box family of transcription factors, activated the mouse alpha A-crystallin promoter in cotransfected COP-8 fibroblasts and bound to the -59 to -29 promoter sequence in EMSAs. These data provide evidence for a synergistic role of Pax-6 and CREB-like proteins for high expression of the mouse alpha A-crystallin gene in the lens.
Cvekl
A
A
Laboratory of Molecular and Developmental Biology, National Eye Institute, Bethesda, Maryland 20892-2730.
Kashanchi
F
F
Sax
C M
CM
Brady
J N
JN
Piatigorsky
J
J
D015124:8-Bromo Cyclic Adenosine Monophosphate / Q000494:pharmacology; D000818:Animals; D001483:Base Sequence; D001665:Binding Sites; D002460:Cell Line; D002467:Cell Nucleus; D003001:Cloning, Molecular; D005576:Colforsin / Q000494:pharmacology; D016384:Consensus Sequence; D003459:Crystallins / Q000096:biosynthesis* / Q000235:genetics*; D051786:Cyclic AMP Response Element Modulator; D017362:Cyclic AMP Response Element-Binding Protein / Q000378:metabolism*; D017931:DNA Primers; D004268:DNA-Binding Proteins / Q000378:metabolism*; D005136:Eye Proteins; D005786:Gene Expression Regulation; D016356:Gene Products, tax / Q000378:metabolism; D018398:Homeodomain Proteins; D015368:Human T-lymphotropic virus 1 / Q000378:metabolism; D006801:Humans; D007908:Lens, Crystalline / Q000378:metabolism*; D051379:Mice / Q000235:genetics*; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D000071841:PAX6 Transcription Factor; D051761:Paired Box Transcription Factors; D016133:Polymerase Chain Reaction; D011401:Promoter Regions, Genetic; D011817:Rabbits; D012045:Regulatory Sequences, Nucleic Acid; D012097:Repressor Proteins / Q000378:metabolism; D012689:Sequence Homology, Nucleic Acid; D014157:Transcription Factors / Q000378:metabolism; D014158:Transcription, Genetic; D015533:Transcriptional Activation; D014162:Transfection
D003459:Crystallins; D017362:Cyclic AMP Response Element-Binding Protein; D017931:DNA Primers; D004268:DNA-Binding Proteins; D005136:Eye Proteins; D016356:Gene Products, tax; D018398:Homeodomain Proteins; D000071841:PAX6 Transcription Factor; C000605730:PAX6 protein, human; D051761:Paired Box Transcription Factors; C000605732:Pax6 protein, mouse; D012097:Repressor Proteins; D014157:Transcription Factors; D051786:Cyclic AMP Response Element Modulator; D005576:Colforsin; D015124:8-Bromo Cyclic Adenosine Monophosphate