REGULATION OF SKIN HOMEOSTASIS BY RNA-BINDING PROTEINS - REGULATION OF SKIN HOMEOSTASIS BY RNA-BINDING PROTEINS PROJECT SUMMARY/ABSTRACT One in four Americans are affected by skin disease, intensely motivating an understanding on the mechanisms underlying epidermal homeostasis. RNA-binding proteins (RBPs) and the main arginine methyltransferase PRMT1 are required for the control of keratinocyte proliferation and differentiation. We have identified two nucleolar RNA helicases and multiple PRMT1 targets that are required for normal skin homeostasis. We have also identified PRMT1 itself is an RBP. A long-term goal of my research is to understand homeostatic mechanisms in skin; the goal of this K01 application is to characterize the roles of RBPs in epidermal homeostasis, specifically the two helicases, PRMT1 and PRMT1 target RBPs. In Aim I, we will test our model for PRMT1’s maintenance of the progenitor state in keratinocytes. Our preliminary data indicates that five stable RBP interactors of PRMT1 – which are also targets of its methyltransferase activity – are also required to maintain homeostasis. In Aim IA, we test the consequence of arginine methylation on these RBPs. In Aim IB, we test the effect of these RBPs and their methylation on gene expression in keratinocytes. In Aim II, we test our model for how RNA helicases promote keratinocyte differentiation. Our data suggests two helicases are sequence-specific, pre-mRNA-binding proteins that promote differentiation by departing the nucleolus to regulate splicing and potentially transcription. Our results also suggest that these helicases can form homo- and heterodimers, with the heterodimer being the strongest interaction. In Aim IIA, we will test their role in transcriptional control of keratinocyte differentiation and whether their apparent control of splicing is direct. In Aim IIB, we will evaluate their dimerization state and its relation to their role in homeostasis, splicing and transcription. My background is in RBP biochemistry, bioinformatics, methods development, and CLIP-seq. Over the course of the training period and within the environment of Stanford’s Department of Dermatology, I plan to acquire expertise in (1) epithelial biology, (2) proteomics, (3) machine learning, and (4) statistics. My research interest in skin biology requires this broad skill set, and this research plan will prepare me for an independent career as an academic scientist working on the mechanisms of gene regulation in epithelial tissue.
