Molecular cloning and characterization of the human phosducin-like protein(hPhLP) promoter

Phosducin-like protein (PhLP) is an inducible G beta gamma binding protein which is hypothesized to be a ubiquitous G protein regulator. To elucidate the mechanisms regulating the expression of the human PhLP (hPhLP) gene, we have cloned and characterized its 5'-flanking region. Primer extension ana lysis identified a major transcription initiation site 172 bp upstream of t he ATG start codon. Analysis of the 5'-flanking region revealed that, altho ugh it lacked a TATA box element, the hPhLP promoter did contain several co nsensus binding motifs including AP4,, CCAAT, CREB, NF-kappa B, SP1 and E2F . Transient transfection analyses using a series of 5'-flanking deletion/lu ciferase reporter gene constructs identified a 25 bp sequence (-80 to -55 b p) that is necessary for basal level transcription of the hPhLP gene in all the cell lines investigated. Interestingly, dependent upon the cell line, distinct transcription factors bind to this region suggesting that basal le vel hPhLP gene transcription may be regulated in a tissue-specific manner. (C) 2000 Elsevier Science B.V. All rights reserved.