ABSTRACT
We have cloned the full length of a novel cDNA, named ring finger protein 21 (RNF21), composed of the RING finger-B box-coiled coil (RBCC) domain and the B30.2 domain, which are characteristic of the RBCC-B30.2 family. As a structural feature, the RNF21 cDNA possessed at least three kinds of isoforms, due to alternative splicing, consisting of the long form with the RBCC-RBCC-B30.2 domain, the medium form with the RBCC-B30.2 domain, and the short form with only the RBCC domain. Moreover, respective transcripts corresponding to the three isoforms were detected in various human organs by reverse transcription-PCR and Northern blot analyses. Interestingly, the medium form of the RNF21 mRNA expressed most predominantly was dramatically up-regulated within 8-16 h by interferon stimulation of HeLa cells. These findings suggest that RNF21 is a downstream gene that may mediate interferon's biological action.
Subject(s)
Carrier Proteins/genetics , Zinc Fingers/genetics , Alternative Splicing , Amino Acid Sequence , Animals , Blotting, Northern , COS Cells , Chromosome Banding , Chromosome Mapping , Chromosomes, Human, Pair 11/genetics , Cloning, Molecular , DNA, Complementary/chemistry , DNA, Complementary/genetics , Female , Gene Expression Regulation/drug effects , HeLa Cells , Humans , In Situ Hybridization, Fluorescence , Interferons/pharmacology , Male , Molecular Sequence Data , Protein Isoforms/genetics , Protein Structure, Tertiary , RNA, Messenger/drug effects , RNA, Messenger/genetics , RNA, Messenger/metabolism , Repetitive Sequences, Amino Acid , Sequence Alignment , Sequence Analysis, DNA , Sequence Homology, Amino Acid , Tissue DistributionABSTRACT
Bfp (brain finger protein) is a member of the RING finger protein family, which is highly expressed in the brain. We have previously shown that one copy of the human bfp gene, mapped at 17p11.2, was actually deleted in six of six Smith-Magenis syndrome (SMS) patients. Now we have isolated the mouse bfp cDNA. Using in situ hybridization and immunohistochemistry, the distribution of mouse bfp mRNA and protein was identified especially in neural cells of the cerebral cortex, hippocampus, lateral amygdaloid nucleus, and ventromedial hypothalamus. In primary culture of the whole brain in a neonatal mouse, the Bfp protein was detected in both neuron and glial cells, and its subcellular localization was predominantly in the nucleus, but some amounts were also found in the cytoplasm. The bfp mRNA was also expressed strongly in the marginal zone of brain vesicles, optic stalk, and cartilage primordium, which are part of the critical tissues frequently involved in SMS patients, and in such tissues as nasal epithelium and primordium of follicles in a 13. 5-dpc embryo. Subsequently, its amount in the developing brain further increased during embryogenesis, reaching the highest level in the adult brain. These findings suggest a possibility that Bfp might be involved in the pathogenesis of Smith-Magenis syndrome as a regulator protein related to neural differentiation and function.
Subject(s)
Abnormalities, Multiple/genetics , Brain/metabolism , DNA-Binding Proteins/genetics , Intellectual Disability/genetics , Nerve Tissue Proteins/genetics , Zinc Fingers/genetics , Amino Acid Sequence , Animals , Blotting, Northern , Brain/embryology , Cells, Cultured , Chromosome Mapping , Cloning, Molecular , DNA, Complementary , DNA-Binding Proteins/analysis , DNA-Binding Proteins/chemistry , Fluorescent Antibody Technique , Gene Expression Regulation, Developmental , Humans , Immunohistochemistry , In Situ Hybridization , Mice , Molecular Sequence Data , Nerve Tissue Proteins/analysis , Nerve Tissue Proteins/chemistry , RNA, Messenger/genetics , RNA, Messenger/metabolism , SyndromeABSTRACT
Sodium selenate (selenate), as well as insulin, increased the lipoprotein lipase (LPL) activity in isolated rat fat pads in a time- and dose-dependent manner. The increase effect of selenate was not additive to that of insulin. The action of selenate and insulin was decreased by amiloride and disappeared when Ca2+ was omitted from the incubation medium. Loading of a chelator of intracellular Ca2+ to the fat pads also greatly inhibited the action of selenate. The maximal increase in inositol 1,4,5-trisphosphate (IP3) content was observed with a 30-s incubation of the fat pads with selenate. Dibutyryl cyclic AMP, 3-isobutyl-1-methylxanthine, carbonyl cyanide m-chlorophenylhydrazone, tunicamycin, and monensin all inhibited the increase effect of selenate on the LPL activity to various extents. These results suggest that selenate increases the LPL activity via amiloride- and monensin-sensitive processes, involving the Ca2+ mobilization linked to a rapid increase in the IP3 content in fat pads.