Cloning and functional characterization of the human heterogeneous nuclear ribonucleoprotein type I promoter.

We have cloned and functionally characterized a portion of the human hnRNP I (heterogeneous nuclear ribonucleoprotein type I) gene containing the promoter elements. HnRNP I is an alternative splicing modulator of tissue-specific transcripts that is expressed in three different isoforms. The DNA sequence at the transcription start site, identified by 5'-rapid amplification of cDNA ends, shows a high 'GC' content, lacks canonical TATA sequences and contains multiple putative Sp1 and NF1 transcription factor-binding sites, a GATA box and a CAAT box. By means of a chloramphenicol acetyltransferase reporter construct and deletion analyses, we have identified two regions between -770 bp and -206 bp that had a positive effect on expression activity in HeLa cells.