Nd1, a novel murine Kelch family protein, may play the role of a housekeeping gene

The murine Nd1 gene encodes a novel Kelch family protein and expresses two forms of mRNA, long (Nd1-L) and short (Nd1-S), in various tissues. We characterized the genomic organization of the Nd1 gene, and found that Nd1-L and Nd1-S consist of 16 and nine exons respectively, and that exons I-VIII are shared between them. Three transcription initiation sites were identified in the 5 ' -flanking region and the most 3 ' side (+1) is likely to be a major one. Promoter analysis revealed that the region between positions -247 and -86 was sufficient for expression, and that two Spl-binding sites and one NF-kappaB-binding site in the region were critical for promoter activity. Furthermore, the promoter region lacks a TATA and a CAAT box and has a highly GC-rich region with two important Spl-binding sites. These characteristics of the Nd1 gene promoter are similar to the properties of housekeeping genes. (C) 2001 Elsevier Science B.V. All rights reserved.