Structure and promoter analysis of the human unc-33-like phosphoprotein gene. E-box required for maximal expression in neuroblastoma and myoblasts.

The human unc-33-like phosphoprotein (hUlip/CRMP-4) is a member of a family of developmentally regulated genes that are highly expressed in the nervous system. Mutations in the C. elegans unc-33 gene lead to worms with abnormal movements. The hUlip gene encodes a 570-amino acid protein with 98% homology to its murine (Ulip) (Byk, T., Dobransky, T., Cifuentes-Diaz, C., and Sobel, A. (1996) J. Neurosci. 16, 688-701) and rat (CRMP-4) (Wang, L. H., and Strittmatter, S. M. (1996) J. Neurosci. 16, 6197-6207) counterparts (Gaetano, C., Matsuo, T., and Thiele, C. J. (1997) J. Biol. Chem. 272, 12195-12201). The hUlip gene was isolated from a human genomic library. It contains 15 exons, including an exon defined by an anaplastic oligodendroglioma expressed sequence tag, and spans at least 61.7 kilobases. hUlip lacks sequences corresponding to the first six exons found in unc-33. unc-33 exons correspond to homologous hUlip exons as follows: VII to 1 and 2, VIII to 3-9, IX to 10-12, and X to 13 and 14. Using the hUlip clone 1 phage, fluorescence in situ hybridization analysis indicates that the hybridization signal localizes to human chromosome 5q32. Deletion analysis of 5'-flanking sequences delineated the sequences sufficient to express a reporter gene in both neuroblastoma cells and myoblasts. A consensus MyoD/myogenin binding site is located in a region of the downstream promoter that is nearly identical to its mouse homologue. Mutagenesis shows that this conserved MyoD/myogenin site is necessary for full promoter activity in both myoblasts and neuroblastoma cells.