Related Experiment Video
Updated: Aug 14, 2026

Methods to Discover Alternative Promoter Usage and Transcriptional Regulation of Murine Bcrp1
Published on: May 27, 2016
Fli-1b is generated by usage of differential splicing and alternative promoter
P D Dhulipala1, L Lee, V N Rao
1Department of Human Genetics, Allegheny University of the Health Sciences, Philadelphia, Pennsylvania 19102, USA.
Abstract:
The proto-oncogene Fli-1, a member of Ets family is rearranged or activated through proviral integration in erythroleukemias, induced by Friends' Murine Leukemia Virus. The DNA binding domain (ETS domain) of Fli-1 is fused to the RNA binding domain of EWS by t(11q24:22q12) chromosomal translocation in Ewing's sarcoma and primitive neuroectodermal tumors. Screening of human cDNA libraries has identified two different 5'-termini and alternatively spliced forms of the human Fli-1 gene (Fli-1b), suggesting the possible existence of two independent promoters. The genomic sequence adjacent to the alternate exon of human Fli-1b gene shows functional promoter activity when cloned in promoter-less CAT expression vector and transfected into QT-6 cells. The transcription initiation (CAP) site and minimum promoter region necessary for function were localized. The 5'-flanking regions of human Fli-1b and mouse Fli-1 show 80% homology suggesting conserved promoter regulatory elements. The Fli-1b 5'-flanking sequence lacks canonical TATA or CCAAT boxes but contains a partially conserved TATA-like sequence at position 242. Several transcription factor binding sequences like ATF/CREB, E2A-PBX1, EBP, PEA-3, ETS-2, Sp-1, c-Myc, TBP, GATA-1 and Oct-3 were conserved in the promoter sequence. Functional promoter assays revealed that Fli-1b promoter shows very strong transcriptional activation compared to Fli-1 promoter. We also showed that variant Fli-1b has transcriptional activation properties similar to those of Fli-1. Fli-1b and Fli-1 show differential expression in various hematopoietic cell lines. This differential expression and promoter activities of Fli-1 and Fli-1b suggests that several mechanisms are involved in Fli-1 gene regulation which are mediated by many transcription factors.
Related Concept Videos
RNA Splicing
Conservative Site-specific Recombination and Phase Variation
The recognition sites for Cre recombinase called LoxP...
Alternative RNA Splicing
There are five types of alternative RNA splicing that vary in the ways the pre-mRNA segments are removed or retained in the mature mRNA. The first...
Exon Recombination
Exon shuffling follows “splice frame rules.” Each exon has three reading...
Reporter Genes
Commonly used reporter...

