Publications by authors named "Amanda N Johnson"
Article Synopsis
- Brugada syndrome (BrS) is an inherited heart condition caused by mutations in the sodium channel gene, and a specific family was found to have a rare G145R variant in a different gene, TBX5, associated with BrS.* -
- Researchers created induced pluripotent stem cells (iPSCs) from family members with the G145R variant and studied the resulting heart cells (iPSC-CMs) to analyze their electrical properties and gene expression differences, comparing them with edited versions using CRISPR technology.* -
- The study found that the G145R variant leads to reduced gene activity and abnormal heart cell behavior, specifically affecting sodium currents, while correcting the mutation restored normal function; disruptions in
A rate threshold mechanism regulates MAPK stress signaling and survival.
Proc Natl Acad Sci U S A
January 2021
Cells are exposed to changes in extracellular stimulus concentration that vary as a function of rate. However, how cells integrate information conveyed from stimulation rate along with concentration remains poorly understood. Here, we examined how varying the rate of stress application alters budding yeast mitogen-activated protein kinase (MAPK) signaling and cell behavior at the single-cell level.
View Article and Find Full Text PDFConvergent evolutionary events in independent lineages provide an opportunity to understand why evolution favors certain outcomes over others. We studied such a case where a large set of genes-those coding for the ribosomal proteins-gained -regulatory sequences for a particular transcription regulator (Mcm1) in independent fungal lineages. We present evidence that these gains occurred because Mcm1 shares a mechanism of transcriptional activation with an ancestral regulator of the ribosomal protein genes, Rap1.
View Article and Find Full Text PDFRepressor activator protein 1 (Rap1) performs multiple vital cellular functions in the budding yeast These include regulation of telomere length, transcriptional repression of both telomere-proximal genes and the silent mating type loci, and transcriptional activation of hundreds of mRNA-encoding genes, including the highly transcribed ribosomal protein- and glycolytic enzyme-encoding genes. Studies of the contributions of Rap1 to telomere length regulation and transcriptional repression have yielded significant mechanistic insights. However, the mechanism of Rap1 transcriptional activation remains poorly understood because Rap1 is encoded by a single copy essential gene and is involved in many disparate and essential cellular functions, preventing easy interpretation of attempts to directly dissect Rap1 structure-function relationships.
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