Extracellular signal-regulated kinase 1/2 (Erk1/2) mitogen activated protein kinases (MAPKs) act within a conserved intracellular signaling pathway that canonically includes upstream Ras, Raf (MAP3K) and Mek (MAP2K) proteins. Prior AR49737 efforts demonstrated that Erk1/2 pathway signaling is integral to both epidermal homeostasis as well as to early tumor progression. We identified two Erk1/2-regulated long non-coding RNAs (lncRNAs) with essential roles in epidermal homeostasis, including, ANCR, which is required for epidermal progenitor tissue maintenance, and TINCR, which is required for epidermal differentiation. In searching for proteins that modulate Erk1/2 output, we targeted all Erk1/2 cascade-interacting proteins to identify IQGAP1 as the only MAPK scaffold that was dispensable for Erk1/2- mediated homeostasis but required for Erk1/2-driven tumor progression. This competing renewal will characterize how these Erk1/2 targets and interactors function. First, we will focus on new lncRNAs by defining their mechanistic actions in homeostatic maintenance. Anti-differentiation non-coding RNA (ANCR) is an Erk1/2-sustained, 855 bp lncRNA enriched in a variety of tissue progenitors that sustains the undifferentiated progenitor state. In contrast, terminal differentiation induced non-coding RNA (TINCR) is an Erk1/2- suppressed, differentiation-induced 3693 bp lncRNA containing 10 novel 25bp motifs that is required for epidermal differentiation. These two lncRNAs are each conserved and essential for epidermal homeostasis.
Aim I will test the hypotheses that defining ANCR's RNA, protein, and genomic interactome will yield insight into its mechanism of action and that TINCR acts within a larger RNA-protein complex to prevent degradation of differentiation mRNAs. Second, we will define IQGAP1-dependent Erk1/2 targets in Erk1/2 driven early tumor progression as a means of separating Erk1/2 homeostatic signaling from its tumorigenic actions. During the prior cycle, we identified IQGAP1 as the sole protein among the many Erk1/2 MAPK cascade scaffolds that is required for Erk1/2-mediated carcinogenesis yet is dispensable for tissue maintenance. IQGAP1 can itself interact with numerous other tumor- enabling proteins in addition to Erk1/2, however, including b-catenin, Akt and Cdc42.
Aim II will determine whether the Erk1/2 pathway is the dominant IQGAP1-interacting pathway in this setting and will characterize IQGAP1 targets in homeostasis and tumorigenesis. This proposal will define how the Erk1/2 MAPK pathway sustains homeostasis, yet also drives tumor progression, as a basis for new therapies for diseases of skin and other tissues.

Public Health Relevance

Erk1/2 mitogen activated protein kinases (MAPKs) signal via an ancient pathway that plays an essential role in maintaining healthy body tissues, such as epidermis, but also in enabling tumors to develop. This proposal characterizes key Erk1/2 mediators of both processes.

Agency
National Institute of Health (NIH)
Institute
National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS)
Type
Research Project (R01)
Project #
5R01AR049737-13
Application #
9067241
Study Section
Arthritis, Connective Tissue and Skin Study Section (ACTS)
Program Officer
Baker, Carl
Project Start
2003-04-01
Project End
2019-05-31
Budget Start
2016-06-01
Budget End
2017-05-31
Support Year
13
Fiscal Year
2016
Total Cost
Indirect Cost
Name
Stanford University
Department
Dermatology
Type
Schools of Medicine
DUNS #
009214214
City
Stanford
State
CA
Country
United States
Zip Code
94304
Ransohoff, Julia D; Wei, Yuning; Khavari, Paul A (2018) The functions and unique features of long intergenic non-coding RNA. Nat Rev Mol Cell Biol 19:143-157
Ramanathan, Muthukumar; Majzoub, Karim; Rao, Deepti S et al. (2018) RNA-protein interaction detection in living cells. Nat Methods 15:207-212
Siprashvili, Zurab; Webster, Dan E; Johnston, Danielle et al. (2016) The noncoding RNAs SNORD50A and SNORD50B bind K-Ras and are recurrently deleted in human cancer. Nat Genet 48:53-8
Zarnegar, Brian J; Flynn, Ryan A; Shen, Ying et al. (2016) irCLIP platform for efficient characterization of protein-RNA interactions. Nat Methods 13:489-92
Bao, Xiaomin; Rubin, Adam J; Qu, Kun et al. (2015) A novel ATAC-seq approach reveals lineage-specific reinforcement of the open chromatin landscape via cooperation between BAF and p63. Genome Biol 16:284
Flynn, Ryan A; Martin, Lance; Spitale, Robert C et al. (2015) Dissecting noncoding and pathogen RNA-protein interactomes. RNA 21:135-43
Noderer, William L; Flockhart, Ross J; Bhaduri, Aparna et al. (2014) Quantitative analysis of mammalian translation initiation sites by FACS-seq. Mol Syst Biol 10:748
Jameson, Katherine L; Mazur, Pawel K; Zehnder, Ashley M et al. (2013) IQGAP1 scaffold-kinase interaction blockade selectively targets RAS-MAP kinase-driven tumors. Nat Med 19:626-630
Kretz, Markus; Siprashvili, Zurab; Chu, Ci et al. (2013) Control of somatic tissue differentiation by the long non-coding RNA TINCR. Nature 493:231-5
Sen, George L; Boxer, Lisa D; Webster, Dan E et al. (2012) ZNF750 is a p63 target gene that induces KLF4 to drive terminal epidermal differentiation. Dev Cell 22:669-77

Showing the most recent 10 out of 26 publications