Structure and expression of the human septin gene HCDCREL-1

Septins are a family of highly conserved filament-forming proteins that have been shown to mediate cytokinesis and cytoskeletal organization in fungi and Drosophila. The gene encoding the human septin family member HCDCREL-1 has been shown to be transcribed from a locus immediately adjacent to that of the platelet glycoprotein (GP) Ib b. The HCDCREL-1 gene possesses a non-consensus polyadenylation signal that apparently is not efficiently utilized, resulting in the expression of a readthrough transcript also containing the platelet GPIb beta coding region. As a first step in understanding the regulation and function of HCDCREL-1, we have analyzed the structure of this gene and characterized its expression in a variety of human cells. Our results indicate that the gene is expressed at high levels in platelets and neural tissue, and is transcriptionally complex.