NAC1, a cocaine-regulated POZ/BTB protein interacts with CoREST.
In this report, CoREST was identified as a protein that interacts with NAC1. NAC1 is a cocaine-regulated Pox virus and Zinc finger/Bric-a-brac Tramtrack Broad complex (POZ/BTB) repressor protein, which mediates interactions among several other transcriptional regulators. In the present study, an interaction between NAC1 and CoREST was detected in neuro-2A cells and HEK293T cells. We found that the POZ/BTB domain is necessary and sufficient for interaction with CoREST. Surprisingly, only one of five mutations in the POZ/BTB domain that disrupts homodimer assembly interfered with NAC1 and CoREST interactions. These results indicate that POZ/BTB homodimer formation is not required for NAC1-CoREST interaction. CoREST demonstrated protein-protein interactions with both isoforms of NAC1, sNAC1, and lNAC1. Coimmunoprecipitation studies show that NAC1 and CoREST are physically bound together. To further support the results, a direct interaction was demonstrated in glutathione-S-transferase pull down assays. siRNA directed against NAC1 mRNA significantly reduced NAC1 protein expression and resulted in reversal of CoREST-mediated repression in cells. This interaction between NAC1 and CoREST was not found for other POZ/BTB proteins tested. Endogenous interaction was demonstrated in lysates from rat brain samples. This is the first report to demonstrate that a POZ/BTB protein interacts with CoREST. Taken together, the results indicate that CoREST may be part of the NAC1 repressor mechanism.
Korutla
Laxminarayana
L
Department of Pharmacology, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania 19104, USA.
Degnan
Ryan
R
Wang
Peijie
P
Mackler
Scott A
SA
D000818:Animals; D045744:Cell Line, Tumor; D056970:Co-Repressor Proteins; D004268:DNA-Binding Proteins / Q000378:metabolism*; D005786:Gene Expression Regulation / Q000502:physiology; D006801:Humans; D047468:Immunoprecipitation / Q000379:methods; D051379:Mice; D016296:Mutagenesis / Q000502:physiology; D009419:Nerve Tissue Proteins / Q000235:genetics / Q000378:metabolism*; D009447:Neuroblastoma; D020033:Protein Isoforms / Q000378:metabolism; D012097:Repressor Proteins / Q000378:metabolism*; D014158:Transcription, Genetic; D014162:Transfection / Q000379:methods; D020798:Two-Hybrid System Techniques
D056970:Co-Repressor Proteins; D004268:DNA-Binding Proteins; C484605:Nacc1 protein, mouse; D009419:Nerve Tissue Proteins; D020033:Protein Isoforms; C485650:Rcor2 protein, mouse; D012097:Repressor Proteins