Project description:Transcriptome analysis by RNA-seq of lungs from control and Rfwd2 epithelial-specific conditional knockout mice at embryonic 13.5 day age. RFWD2, is an E3 ubiquitin ligase that modifies specific target proteins, priming their degradation via the ubiquitin proteasome system. Rfwd2 deficiency led to a striking halt in branching morphogenesis shortly after secondary branch formation. In the mutant lung, two ETS transcript factors essential for normal lung branching, ETV4 and ETV5, were upregulated at the protein, but not transcript level. Introduction of Etv loss-of-function alleles into the Rfwd2 mutant background attenuated the branching phenotype, suggesting that RFWD2 functions at least in part through degrading ETV proteins. As a number of E3 ligases are known to target factors important for lung development, our findings provides a preview of a protein-level regulatory network essential for lung branching morphogenesis.
Project description:FBXW7 is and E3 ubiquitin ligase and is highly mutated in colorectal cancer. We used human colon organoids with engineered FBXW7 hotspot mutations to investigate novel targets of E3 ligase activity with a combined transcriptomic and proteomic approach uncovering the EGFR-MAPK pathway as highly regulated by the E3 ligase activity.
