Integrin alpha v promoter activity in keratinocytes.
BACKGROUND
During reepithelialization keratinocytes show increased expression of the integrin subunit alpha-v. We have investigated the promoter region of the alpha-v integrin subunit to learn more about its regulation.


METHODS
The promoter region of the human integrin alpha-v gene was cloned into a luciferase reporter vector. Deletional mutants were created using PCR. Computerized sequence analysis was performed using the Wisconsin Package. Gel-shift analysis was performed using keratinocyte nuclear extracts and oligonucleotides spanning th regions of interest.


RESULTS
Deletion from -522 bp to -235 resulted in no discernible effect on promoter activity. In contrast deletion of the next 22 bp, which included a putative ets binding site, reduced activity by approximately half. Further deletion to -139 bp essentially abolished promoter activity. Computer searching of this region of the integrin alpha-v promoter revealed two tandemly repeated motifs, TCCTCCTCC, that had previously been implicated in the function of the epidermal growth factor receptor (EGFR) promoter. Comparison of the alpha-v integrin promoter to the EGFR promoter revealed an area of high homology in this region. Gel-shift analysis revealed binding of a single-strand specific DNA binding protein to single stranded oligos comprising these motifs, but no binding of factors to the double- stranded oligo containing the ets binding site.


CONCLUSIONS
In keratinocytes alpha-v integrin expression is controlled by a region of the promoter with high homology to the epidermal growth factor receptor promoter This region binds single-strand specific DNA binding proteins that are likely to be important in controlling transcription.
Department of Surgery, University of Texas Southwestern Medical Center, Dallas, USA.
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LT
Kim
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Wu
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Turnage
D015703:Antigens, CD / Q000235:genetics*; D001483:Base Sequence; D001665:Binding Sites; D004277:DNA, Single-Stranded / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000378:metabolism; D004815:Epidermal Growth Factor / Q000235:genetics; D017353:Gene Deletion; D006801:Humans; D039564:Integrin alphaV; D015603:Keratinocytes / Q000378:metabolism*; D008156:Luciferases / Q000235:genetics; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic; D012091:Repetitive Sequences, Nucleic Acid; D017385:Sequence Homology; D014162:Transfection
D015703:Antigens, CD; D004277:DNA, Single-Stranded; D004268:DNA-Binding Proteins; D039564:Integrin alphaV; D004815:Epidermal Growth Factor; D008156:Luciferases