Signaling pathways in which GCK group Mst/hippo kinases regulate AGC group Ndr/LATS kinases are ancient controllers of growth, proliferation, and architecture of eukaryotic cells. Our broad goal is to define the diverse intracellular processes these pathways regulate and determine the mechanisms underlying this control. Forms of Mst/hippo signaling (hippo-warts pathways) that suppress metazoan cell proliferation in metazoans by inhibiting YAP/yorkie-related transcriptional co-activators have been the subject of intensive recent interest. However, the distinct and highly conserved hippo-trc form of this pathway in which large furry related proteins mediate Mst/hippo kinase activation of Ndr/tricornered kinases have dramatically different functions; comparatively little is known about them, and they are the focus of this project. The hippo-trc pathways are important for polarized growth and organization of cellular extensions, neuron morphogenesis, mitotic spindle organization, and positive regulation of cell proliferation. We have successfully studied the system in budding yeast, which use a conserved hippo-trc pathway known as the RAM network to control cell division and polarized growth. Under close regulation by mitotic exit machinery, this pathway directly drives asymmetric localization and activity of a transcription factor that turns on expression of genes involved in the final step of cytokinesis. In addition to this primordial cell fate decision, budding yeast hippo-trc signaling promotes maintenance of cell polarity and regulates translation of proteins required for physical expansion of the cell during rapid growth. This project aims to define the regulatory mechanisms and downstream targets of Cbk1. Through combined computational and experimental work we have discovered that a novel docking motif peptide recruits this Ndr/LATS kinase to in vivo substrates through interaction with the kinase catalytic domain. We have crystallized the Mob2-Cbk1 complex and solved its structure, the first for any Ndr/LATS kinase, and will use this information to guide analysis of the kinase's activation mechanisms. We will define how the docking motif binds to Cbk1's kinase domain, analyze effects caused by disruption of this interaction in vivo, and determine if the novel substrate docking behavior we have discovered in budding yeast also occurs with metazoan orthologs. When combined with existing interaction and phosphoproteomic data, our analysis of substrate docking and consensus motif conservation at least triples the number of high confidence Cbk1 targets. In addition to extending our analysis of the pathway's regulation of mRNA translation, we will explore this expanded regulatory network to gain a more comprehensive mechanistic understanding of this hippo-trc pathway's control of cell division and morphogenesis.

Public Health Relevance

The core signaling systems that direct the behavior of cells are over a billion years old, and when they function properly they ensure correct organization of cells in normal tissues. In contrast, derangement of signaling underlies deadly and debilitating illnesses, such as cancer and birth defects. We are using budding yeast to understand the fundamental biochemical and cell biological mechanisms of an ancient but poorly understood 'Ndr/LATS' signaling system. In humans, such control pathways are crucial for normal growth, proliferation, and architecture of cells.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
5R01GM084223-09
Application #
9285809
Study Section
Cellular Signaling and Regulatory Systems Study Section (CSRS)
Program Officer
Melillo, Amanda A
Project Start
2008-05-01
Project End
2018-02-28
Budget Start
2017-03-01
Budget End
2018-02-28
Support Year
9
Fiscal Year
2017
Total Cost
$256,682
Indirect Cost
$83,432
Name
Northwestern University at Chicago
Department
Biochemistry
Type
Schools of Arts and Sciences
DUNS #
160079455
City
Evanston
State
IL
Country
United States
Zip Code
60201
Gógl, Gerg?; Schneider, Kyle D; Yeh, Brian J et al. (2015) The Structure of an NDR/LATS Kinase-Mob Complex Reveals a Novel Kinase-Coactivator System and Substrate Docking Mechanism. PLoS Biol 13:e1002146
Wanless, Antony G; Lin, Yuan; Weiss, Eric L (2014) Cell morphogenesis proteins are translationally controlled through UTRs by the Ndr/LATS target Ssd1. PLoS One 9:e85212
Hsu, Jonathan; Weiss, Eric L (2013) Cell cycle regulated interaction of a yeast Hippo kinase and its activator MO25/Hym1. PLoS One 8:e78334
Weiss, Eric L (2012) Mitotic exit and separation of mother and daughter cells. Genetics 192:1165-202
Boettcher, Barbara; Marquez-Lago, Tatiana T; Bayer, Mathias et al. (2012) Nuclear envelope morphology constrains diffusion and promotes asymmetric protein segregation in closed mitosis. J Cell Biol 197:921-37
Nguyen Ba, Alex N; Yeh, Brian J; van Dyk, Dewald et al. (2012) Proteome-wide discovery of evolutionary conserved sequences in disordered regions. Sci Signal 5:rs1
Brace, Jennifer; Hsu, Jonathan; Weiss, Eric L (2011) Mitotic exit control of the Saccharomyces cerevisiae Ndr/LATS kinase Cbk1 regulates daughter cell separation after cytokinesis. Mol Cell Biol 31:721-35
Mazanka, Emily; Weiss, Eric L (2010) Sequential counteracting kinases restrict an asymmetric gene expression program to early G1. Mol Biol Cell 21:2809-20
Jansen, Jaclyn M; Wanless, Antony G; Seidel, Christopher W et al. (2009) Cbk1 regulation of the RNA-binding protein Ssd1 integrates cell fate with translational control. Curr Biol 19:2114-20