Genomic structure and regulation of a novel human gene, Klp1.

Klp1 (K562 cells-derived leucine zipper-like protein 1) is a transcription factor which binds to the coproporphyrinogen oxidase promoter regulatory element (GGACTACAG). In order to clarify the function of Klp1, we determined the complete human Klp1 genomic structure and regulatory element in the promoter region. The gene spans about 2.4 kb and has three exons. Its promoter region has multiple GC boxes, E2F binding site, one cAMP response element (CRE), and no TATA box with multiple transcription initiation sites, which is characteristic of housekeeping and growth regulating genes. Promoter analysis showed that the promoter was more active in K562 cells entered into the cell cycle by serum stimulation than quiescent cells. Further promoter analysis revealed that CRE at -42 is essential for full promoter activity, and c-Jun and activation transcription factor 1/cAMP response element binding protein 1 proteins bind to this element. These structural characteristics and the promoter function suggest that Klp1 may play a role in cell cycle regulation.