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/

Citation
A. Cvekl et al., 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/, Molecular and cellular biology, 15(2), 1995, pp. 653-660
Citations number
80
Categorie Soggetti
Biology
ISSN journal
02707306
Volume
15
Issue
2
Year of publication
1995
Pages
653 - 660
Database
ISI
SICI code
0270-7306(1995)15:2<653:TROTMA>2.0.ZU;2-X
Abstract
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[AIC] [A/G]3'), behaves like a functional CRE s ite. Transfection experiments and electrophoretic mobility shift assay s (EMSAs) using site-specific mutations correlated a loss of function with deviations from the CRE consensus sequence. Results of EMSAs in t he presence of antisera against CREE, Delta CREB, and CREM were consis tent with the binding of CREB-like proteins to the DE1 sequence. Stimu lation of alpha A-crystallin promoter activity via 8-bromo-cAMP, forsk olin, or human T-cell leukemia virus type I Tax(1) in transfections an d reduction of activity of this site in cell-free transcription tests by competition with the somatostatin CRE supported the idea that DEI i s a functional CRE. Finally, Pax-6, a member of the paired-box family of transcription factors, activated the mouse alpha A-crystallin promo ter in cotransfected COP-8 fibroblasts and bound to the -59 to -29 pro moter 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.