Publications by authors named "Eyan Yeung"
Article Synopsis
- The maternal-to-zygotic transition (MZT) shifts developmental control from maternal proteins to those produced by the zygote, with over half of the Drosophila melanogaster genome coding for maternal proteins.
- About 2% of these proteins are quickly degraded during MZT, including key post-transcriptional repressors such as Cup and SMG.
- The degradation is facilitated by specific protein complexes: the CTLH complex targets several repressors early on, while the SCF complex targets SMG later, suggesting a coordinated process essential for proper MZT progression.
Multisite protein phosphorylation plays a critical role in cell regulation [1-3]. It is widely appreciated that the functional capabilities of multisite phosphorylation depend on the order and kinetics of phosphorylation steps, but kinetic aspects of multisite phosphorylation remain poorly understood [4-6]. Here, we focus on what appears to be the simplest scenario, when a protein is phosphorylated on only two sites in a strict, well-defined order.
View Article and Find Full Text PDFOptogenetic approaches are transforming quantitative studies of cell-signaling systems. A recently developed photoswitchable mitogen-activated protein kinase kinase 1 (MEK1) enzyme (psMEK) short-circuits the highly conserved Extracellular Signal-Regulated Kinase (ERK)-signaling cascade at the most proximal step of effector kinase activation. However, since this optogenetic tool relies on phosphorylation-mimicking substitutions in the activation loop of MEK, its catalytic activity is predicted to be substantially lower than that of wild-type MEK that has been phosphorylated at these residues.
View Article and Find Full Text PDFQuantitative analysis of proteomes across multiple time points, organelles, and perturbations is essential for understanding both fundamental biology and disease states. The development of isobaric tags (e.g.
View Article and Find Full Text PDFThe MEK1 kinase directly phosphorylates ERK2, after the activation loop of MEK1 is itself phosphorylated by Raf. Studies over the past decade have revealed a large number of disease-related mutations in the gene that lead to tumorigenesis and abnormal development. Several of these mutations result in MEK1 constitutive activity, but how they affect MEK1 regulation and function remains largely unknown.
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- Germline mutations in components of the Ras pathway lead to developmental disorders called RASopathies, which include issues like heart defects and cognitive delays.
- Researchers studied mutations in the MAP2K1 gene in fruit flies and zebrafish to examine how these mutations affect Ras pathway signaling.
- They found that certain active variants of the MEK protein can both enhance and reduce signaling levels depending on the cell context, suggesting that both increases and decreases in Ras signaling may contribute to the symptoms of RASopathies.
A variety of cellular pathways are regulated by protein modifications with ubiquitin-family proteins. SUMO, the Small Ubiquitin-like MOdifier, is covalently attached to lysine on target proteins via a cascade reaction catalyzed by E1, E2, and E3 enzymes. A major barrier to understanding the diverse regulatory roles of SUMO has been a lack of suitable methods to identify protein sumoylation sites.
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