ABSTRACT
NF-kappaB-repression factor (NRF) is a nuclear inhibitor of NF-kappaB proteins that can silence the IFNbeta promoter. Since NRF was cloned in 1999, in-depth studies have been conducted on the biological functions of this constitutive repressor of NF-kappaB proteins. During large-scale sequencing of a human fetal brain cDNA library we isolated a novel human cDNA that proved to be a correct full-length NRF cDNA. The deduced protein contains 690 aa, and has a G-patch and an R3H domain at its C-terminus. The size of the protein is consistent with its counterparts in mouse and rat. There is considerable evidence that there are some mistakes in the NRF cDNA sequence reported by Nourbakhsh. Here we report the correct, full-length cDNA and protein sequences of NRF. Full-length NRF cDNA is 3247 bp long, contains three exons and maps to human chromosome Xq24. RT-PCR shows that NRF is widely expressed in human tissues.
Subject(s)
DNA-Binding Proteins/genetics , NF-kappa B/antagonists & inhibitors , Repressor Proteins/genetics , Transcription Factors/genetics , Amino Acid Sequence , Base Sequence , Cloning, Molecular , DNA, Complementary , DNA-Binding Proteins/metabolism , Humans , Molecular Sequence Data , Repressor Proteins/metabolism , Sequence Analysis, DNA , Transcription Factors/metabolismABSTRACT
The mutation of human cereblon gene (CRBN) is revealed to be related with mild mental retardation. Since the molecular characteristics of CRBN have not been well presented, we investigated the general properties of CRBN. We analyzed its gene structure and protein homologues. The CRBN protein might belong to a family of adenosine triphosphate (ATP)-dependent Lon protease. We also found that CRBN was widely expressed in different tissues, and the expression level in testis is significantly higher than other tissues. This may suggested it could play some important roles in several other tissues besides brain. Transient transfection experiment in AD 293 cell lines suggested that both CRBN and CRBN mutant (nucleotide position 1,274(C > T)) are located in the whole cells. This may suggest new functions of CRBN in cell nucleolus besides its mitochondria protease activity in cytoplasm.