A role for the transcriptional repressor REST in maintaining the phenotype of neurosecretory-deficient PC12 cells.
The rat PC12 variant cell line, A35C, lacks regulated secretory organelles due to a selective transcriptional block. Hence, A35C may provide clues about the mechanisms that underlie control of neurosecretion. We used mRNA microarray profiling to examine gene expression in A35C. Genes for regulated secretory proteins were down-regulated, while other membrane trafficking pathways were unaffected. A subset of genes repressed in A35C contain binding sites for the neuronal transcriptional repressor, RE1-silencing transcription factor (REST), and REST is expressed in A35C but not normal PC12 cells. Blocking the activity of REST in A35C using a dominant-negative construct induced the reappearance of mRNAs for synaptophysin, chromogranin A, synaptotagmin IV and the beta3 subunit of the voltage-gated sodium channel (Scn3b), all of which contain RE1 sites in their genes. In the case of Scn3b, the corresponding protein was also re-expressed. Granule and synaptic vesicle proteins were not re-expressed at the protein level, despite reactivation of their mRNA, suggesting the existence of additional post-transcriptional control for these proteins. Our work identifies one of the mechanisms underlying the phenotype of neurosecretory-deficient neuroendocrine cells, and begins to define the critical components that determine a key aspect of the neuroendocrine phenotype.
Pance
Alena
A
Department of Biochemistry, University of Cambridge, Cambridge, UK.
Livesey
Frederick J
FJ
Jackson
Antony P
AP
D000818:Animals; D001665:Binding Sites / Q000235:genetics; D053379:Chromogranin A / Q000235:genetics / Q000378:metabolism; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation / Q000502:physiology*; D009474:Neurons / Q000378:metabolism*; D009489:Neurosecretion / Q000235:genetics*; D009490:Neurosecretory Systems / Q000378:metabolism* / Q000503:physiopathology; D016716:PC12 Cells; D010641:Phenotype; D017729:Presynaptic Terminals / Q000378:metabolism; D011499:Protein Processing, Post-Translational / Q000235:genetics; D012333:RNA, Messenger / Q000032:analysis / Q000235:genetics / Q000378:metabolism; D051381:Rats; D050436:Regulatory Elements, Transcriptional / Q000235:genetics; D012097:Repressor Proteins / Q000235:genetics / Q000378:metabolism*; D022142:Secretory Vesicles / Q000378:metabolism; D015222:Sodium Channels / Q000235:genetics / Q000378:metabolism; D016708:Synaptophysin / Q000235:genetics / Q000378:metabolism; D050857:Synaptotagmins / Q000235:genetics / Q000378:metabolism; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D062549:Voltage-Gated Sodium Channel beta-3 Subunit; D000099229:RE1-Silencing Transcription Factor
D053379:Chromogranin A; D012333:RNA, Messenger; D012097:Repressor Proteins; D015222:Sodium Channels; D016708:Synaptophysin; D050857:Synaptotagmins; D014157:Transcription Factors; D062549:Voltage-Gated Sodium Channel beta-3 Subunit; D000099229:RE1-Silencing Transcription Factor; C493324:SCN3B protein, human