NSPc1, a mainly nuclear localized protein of novel PcG family members, has a transcription repression activity related to its PKC phosphorylation site at S183.
Nervous system polycomb 1 (NSPc1) shares high homology with vertebrate PcG proteins Mel-18 and Bmi-1. The mRNA of NSPc1 is highly expressed in the developmental nervous system [Mech. Dev. 102 (2001) 219-222]. However, the functional characterization of NSPc1 protein is not clear. In the present study, using Western blotting technique, we aimed to describe the distributions of NSPc1 protein in rat tissues and cell lines. The subcellular localization of NSPc1 was examined in HeLa and SH-SY5Ycell lines, and its transcriptional repression activity was examined in COS-7 cell line. We found that the NSPc1 protein was localized mainly in the nucleus. NSPc1 remarkably repressed the transcription. Most interestingly, both the C-terminal of NSPc1 and two phosphorylation sites in the C-terminal, especially the PKC phosphorylation site at S183, were important in mediating transcription repression. Taken together, results from our study suggest that NSPc1, as a typical PcG family member, has powerful transcriptional repression ability, which may be related to the PKC signaling pathway.
Gong
Yanhua
Y
Institute of Basic Medical Sciences, National Laboratory of Medical Molecular Biology, Chinese Academy of Medical Sciences and Peking Union Medical College, National Human Genome Center, Beijing 100005, China.
Wang
Xu
X
Liu
Jin
J
Shi
Lei
L
Yin
Bin
B
Peng
Xiaozhong
X
Qiang
Boqin
B
Yuan
Jiangang
J
D000818:Animals; D002352:Carrier Proteins / Q000032:analysis / Q000737:chemistry / Q000378:metabolism*; D002460:Cell Line; D002467:Cell Nucleus / Q000737:chemistry / Q000378:metabolism; D005786:Gene Expression Regulation; D017930:Genes, Reporter / Q000235:genetics; D006801:Humans; D008156:Luciferases / Q000032:analysis / Q000235:genetics; D016296:Mutagenesis / Q000235:genetics; D009154:Mutation / Q000235:genetics; D009687:Nuclear Proteins / Q000032:analysis / Q000737:chemistry / Q000378:metabolism*; D010766:Phosphorylation; D063150:Polycomb Repressive Complex 1; D011493:Protein Kinase C / Q000378:metabolism*; D051381:Rats; D012097:Repressor Proteins / Q000032:analysis / Q000737:chemistry / Q000378:metabolism*; D014018:Tissue Distribution; D014158:Transcription, Genetic; D044767:Ubiquitin-Protein Ligases / Q000032:analysis / Q000737:chemistry / Q000378:metabolism*
D002352:Carrier Proteins; D009687:Nuclear Proteins; C496334:PCGF1 protein, human; D012097:Repressor Proteins; D008156:Luciferases; D063150:Polycomb Repressive Complex 1; D044767:Ubiquitin-Protein Ligases; D011493:Protein Kinase C