Title: Modeling POLR2A syndrome in human cells
Abstract:
RNA polymerase II is an essential protein complex that transcribes all protein coding genes in eukaryotes. Recently, a human disease was described where individuals had mutations in POLR2A, encoding the largest subunit of RNA polymerase II. Haijes et al, 2019 identified individuals with various neurodevelopmental and neuromuscular issues who each had mutations in POLR2A. However, the severity of the observed phenotypes ranges between mutations and the underlying causes remain unclear. Bioinformatics tools that predict the deleterious impact of missense mutations are unable to predict mutant severity that matches with patient symptom severity. One hypothesis is the observed phenotypes result from defects in transcription during early neurodevelopment, which may be sensitive to environment, genetic background, and stochastic effects. To determine how these POLR2A mutations result in transcriptional defects, total and nascent transcriptome analysis in HEK293T cells will be performed on four disease alleles associated with a range of phenotype severity. To discover how these transcription defects affect cellular differentiation, similar transcriptome analyses will be conducted on mutant mouse embryonic stem cells (mESCs) induced to differentiate to neural progenitor cells (NPCs). The observation of any defects from these transcriptome analyses would provide evidence for potential disease-causing mechanisms. Determining if severe disease alleles result in a higher magnitude of transcription defects may explain the range of severity between observed phenotypes.
Kaplan Lab
Friday, November 10th, 2023
12:00PM
Langley A219B