Recently, Pdx1 has been shown to recruit numerous coregulatory proteins that participate in modulating its activity in vitro. Most interestingly, interactions between Pdx1 and specific coregulators are often compromised in beta cells of Type 2 diabetic donors.
The Spaeth Lab is currently addressing the limited knowledge in the islet field regarding coregulators and their dynamic control of transcription factor actions. Specifically, the lab investigates the mechanisms by which the Pdx1-recruited Swi/Snf chromatin remodeling complex, the Chd3/Chd4/Nucleosome Remodeling (NuRD) complex, the Snd1 coactivator, and the Myst2 histone acetyltransferase contribute to Pdx1 transcriptional activity and beta cell function using cell culture and animal model systems.
The Spaeth Lab employs biochemical assays including immunoprecipitation (IP), proximity ligation assays (PLA) and chromatin immunoprecipitation (ChIP) to characterize interactions between coregulators and transcription factors. Team members in the Spaeth Lab study the effects on: 1) Pdx1-target gene expression by qCPR and RNA-sequencing and 2) beta cell function by glucose stimulated insulin secretion following RNAi-mediated depletion of key components of the coregulatory complexes in rodent and human beta cells lines. Additionally, the laboratory uses mouse models to study the in vivo roles of these factors via Cre/Lox technology, with special emphasis on beta cell development and postnatal beta cell function.