Wildtype Elk-1, but not a SUMOylation mutant, represses egr-1 expression in SH-SY5Y neuroblastomas.
Elk-1, an ETS domain transcription factor of the TCF (ternary complex factor) subfamily, is known to be involved in the regulation of immediate-early genes such as c-fos upon mitogen activation, and thus commonly implied in cell proliferation. Early growth response-1, Egr-1, which was known to be an immediate-early gene, has recently been shown to be pro-apoptotic for SH-SY5Y neuroblastoma cells. In that respect, it was not clear whether Elk-1 would activate or repress from this promoter, since Elk-1 is mostly associated with proliferation and not apoptosis. In this study, we wanted to address whether Elk-1 activates or represses egr-1 promoter in neuroblastoma cells, and using a combination of RNA interference and reporter analyses, we present evidence that egr-1 gene is repressed by Elk-1 in normally cycling SH-SY5Y neuroblastoma cell line in a SUMO (small ubiquitin-related modifier)-dependent manner, a potential mechanism used by these cells to bypass apoptosis.
Demir
O
O
Yeditepe University, Department of Genetics and Bioengineering, Istanbul, Turkey. odemir@yeditepe.edu.tr
Kurnaz
I Aksan
IA
D017209:Apoptosis / Q000502:physiology; D001932:Brain Neoplasms / Q000235:genetics; D045744:Cell Line, Tumor; D051766:Early Growth Response Protein 1 / Q000096:biosynthesis* / Q000235:genetics; D016762:Genes, fos / Q000235:genetics; D006801:Humans; D020928:Mitogen-Activated Protein Kinases / Q000235:genetics; D009154:Mutation / Q000235:genetics; D009447:Neuroblastoma / Q000235:genetics; D010766:Phosphorylation; D034622:RNA Interference; D012694:Serine / Q000235:genetics; D025841:Small Ubiquitin-Related Modifier Proteins / Q000235:genetics*; D050807:ets-Domain Protein Elk-1 / Q000235:genetics*
C494112:ELK1 protein, human; D051766:Early Growth Response Protein 1; D025841:Small Ubiquitin-Related Modifier Proteins; D050807:ets-Domain Protein Elk-1; D012694:Serine; D020928:Mitogen-Activated Protein Kinases