Intrinsically asymmetric cell division, in which a polarized mother cell divides to create daughters with intrinsically different fates, is a fundamental process with critical roles in development, and possible roles in tissue maintenance in the adult life of mammals. To understand asymmetric cell divisions it is necessary to understand the generation and maintenance of cell polarity. Elucidating mechanisms for the establishment and maintenance of cell polarity is an important goal not only because it is central to understanding asymmetric cell division but also because cell polarity is the foundation for the proper development and function of most tissue and organ systems. Failures in cell polarity are a contributing factor in the development of cancer. The proposed research continues ongoing analysis of the generation of cell polarity during the asymmetric divisions of the model organism Caenorhabditis elegans with a particular focus on the role of the PAR proteins in establishing cell polarity in the early embryo. PAR proteins are evolutionarily conserved regulators of cell polarity with roles in a variety of cell types including polarized epithelial cells, neurons, oocytes and migratory cells of many types. Project goals include: 1) Determining the mechanism by which the conserved polarity protein and tumor suppressor LGL-1 restricts PAR proteins to one pole of the cell. 2) Determining the mechanism by which two conserved de-ubiquitinating enzymes regulate the asymmetric localization of the PAR proteins. 3) Using carbon nano-pipettes to develop a microinjection system and using that system to introduce compounds and proteins at specific times and locations in the early embryo to understand the initial events in polarity establishment.

Public Health Relevance

The proposed research studies the role of PAR proteins in establishing and maintaining cell polarity, which is a fundamental property of most cells and is critical to tissue and organ function. Loss of cell polarity is a factor in the development of cancer;indeed, one of the genes being studied is a known tumor suppressor.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
5R01GM079112-23
Application #
8681464
Study Section
Development - 1 Study Section (DEV1)
Program Officer
Hoodbhoy, Tanya
Project Start
1991-02-05
Project End
2015-06-30
Budget Start
2014-07-01
Budget End
2015-06-30
Support Year
23
Fiscal Year
2014
Total Cost
Indirect Cost
Name
Cornell University
Department
Biochemistry
Type
Earth Sciences/Resources
DUNS #
City
Ithaca
State
NY
Country
United States
Zip Code
14850
Watts, Jason S; Morton, Diane G; Kemphues, Kenneth J et al. (2018) The biotin-ligating protein BPL-1 is critical for lipid biosynthesis and polarization of the Caenorhabditis elegans embryo. J Biol Chem 293:610-622
Brennan, Lucy D; Roland, Thibault; Morton, Diane G et al. (2013) Small molecule injection into single-cell C. elegans embryos via carbon-reinforced nanopipettes. PLoS One 8:e75712
Beatty, Alexander; Morton, Diane G; Kemphues, Kenneth (2013) PAR-2, LGL-1 and the CDC-42 GAP CHIN-1 act in distinct pathways to maintain polarity in the C. elegans embryo. Development 140:2005-14
McCloskey, Richard J; Kemphues, Kenneth J (2012) Deubiquitylation machinery is required for embryonic polarity in Caenorhabditis elegans. PLoS Genet 8:e1003092
Mi-Mi, Lei; Votra, SarahBeth; Kemphues, Kenneth et al. (2012) Z-line formins promote contractile lattice growth and maintenance in striated muscles of C. elegans. J Cell Biol 198:87-102
He, Yin; Beatty, Alexander; Han, Xuemei et al. (2012) Nonmuscle myosin IIB links cytoskeleton to IRE1? signaling during ER stress. Dev Cell 23:1141-52
Morton, Diane G; Hoose, Wendy A; Kemphues, Kenneth J (2012) A genome-wide RNAi screen for enhancers of par mutants reveals new contributors to early embryonic polarity in Caenorhabditis elegans. Genetics 192:929-42
Li, Bingsi; Kim, Heon; Beers, Melissa et al. (2010) Different domains of C. elegans PAR-3 are required at different times in development. Dev Biol 344:745-57
Li, Jin; Kim, Heon; Aceto, Donato G et al. (2010) Binding to PKC-3, but not to PAR-3 or to a conventional PDZ domain ligand, is required for PAR-6 function in C. elegans. Dev Biol 340:88-98
Beatty, Alexander; Morton, Diane; Kemphues, Kenneth (2010) The C. elegans homolog of Drosophila Lethal giant larvae functions redundantly with PAR-2 to maintain polarity in the early embryo. Development 137:3995-4004

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