Identification of a nuclear localization signal in the retinitis pigmentosa-mutated RP26 protein, ceramide kinase-like protein.

Abstract

Retinitis pigmentosa (RP) is a genetically heterogeneous disease characterized by degeneration of the retina. A mutation in a new ceramide kinase (CERK) homologous gene, named CERK-like protein (CERKL), was found to cause autosomal recessive retinitis pigmentosa (RP26). Here, we show a point mutation of one of two putative nuclear localization signal (NLS) sequences inhibited the nuclear localization of the protein. Furthermore, the tetra-GFP-tagged NLS, which cannot passively enter the nucleus, was observed not only in the nucleus but also in the nucleolus. Our results provide the first evidence of the active nuclear import of CERKL and suggest that the identified NLS might be responsible for nucleolar retention of the protein. As recent studies have shown other RP-related proteins are localized in the nucleus or the nucleolus, our identification of NLS in CERKL suggests that CERKL likely plays important roles for retinal functions in the nucleus and the nucleolus.

• Authors: Yuichi Inagaki, Susumu Mitsutake, Yasuyuki Igarashi
• Journal: Biochemical and biophysical research communications (Biochem Biophys Res Commun) Vol. 343 Issue 3 Pg. 982-7 (May 12 2006) ISSN: 0006-291X [Print] United States
• PMID: 16581028 (Publication Type: Journal Article)

Chemical References

• Ceramides
• Nuclear Localization Signals
• Phosphotransferases (Alcohol Group Acceptor)
• ceramide kinase

Topics

• Active Transport, Cell Nucleus
• Animals
• Cell Line
• Cell Nucleolus (enzymology)
• Cell Nucleus (enzymology)
• Ceramides (metabolism)
• Humans
• Nuclear Localization Signals
• Phosphotransferases (Alcohol Group Acceptor) (chemistry, genetics, metabolism)
• Point Mutation