Nucleolar Protein 4 (NOL4)

Ueki et al. (1998) cloned a cDNA encoding a novel nucleolar protein, termed NOLP for 'nucleolar-localized protein,' from a human fetal brain cDNA library. The NOLP gene encodes a 524-amino acid polypeptide with an E. coli helicase-homologous region, an acid-rich domain, 3 base-rich putative nuclear localization signals, a serine-rich region, and a coiled-coil domain. Northern blot analysis and RT-PCR revealed that NOLP is expressed as a 3.5-kb mRNA in fetal brain, adult brain, and testis. Deletion studies revealed that NOLP contains functional nuclear and nucleolar localization signals. Using ESTs, Ueki et al. tentatively mapped the NOL4 gene to 18q12. In a study of sequence homology between human chromosome 20 and mouse chromosome 2, Zhu et al. (2003) placed the NOL4 gene on human chromosome 20.