Submitted on December 4, 2003
Accepted on February 17, 2004
Genomic structure and promoter characterization of the human Sprouty4 gene, a novel regulator of lung morphogenesis
Wei Ding1*, Saverio Bellusci1, Wei Shi1, and David Warburton1
1 Department of Pediatric Surgery, Childrens Hospital Los Angeles, Saban Research Institute, Los Angeles, CA, USA
* To whom correspondence should be addressed. E-mail: wding{at}chla.usc.edu.
The expression of Sprouty4 (Spry4), an intracellular FGF receptor antagonist, shows a temporally and spatially restricted pattern in embryonic lung and is induced by ERK signaling. In order to clarify the molecular mechanisms regulating Sprouty4 transcription, the genomic structure of the human Sprouty4 (hSpry4) gene was first determined by using the GenomeWalker kit. The hSpry4 gene spans > 14 kb and is organized in three exons and two introns. Multiple transcription start sites were subsequently mapped by 5'-rapid amplification of cDNA ends. Analysis of up to 4-kb of
sequence in the 5'-flanking region of the gene showed the presence of multiple potential transcription factor binding sites, but no TATA or CAAT boxes. Transient transfection
using luciferase reporter gene constructs with progressive deletions of the Spry4 5'- flanking region revealed that the core promoter activity is located within the proximal 0.4-kb region, whereas the minimal ERK-inducible promoter activity is between -69 and -31. Homology analysis further showed that the core promoter region of the human
Sprouty4 gene exhibits significant similarity to the 5'-flanking region of the mouse gene.
