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Principal Investigator: NATALIE G. AHN
Organization: UNIVERSITY OF COLORADO
Fiscal Year: 2019
Award: $286,400
Funding agency: National Institute of General Medical Sciences
PROJECT SUMMARY
An important unsolved question is how extracellular signals lead to force-generating events needed for cell
migration. Cell locomotion requires coordination between localized membrane protrusions and matrix
attachments at the cell front, and localized retraction and disassembly of adhesions at the rear. Signaling
pathways which control protein movement to the rear of cells are poorly understood, and involve rear-polarized
elevation of actomyosin and Ca2+, through mechanisms that have not been fully explained. This proposal
addresses a recently discovered intracellular complex, named the “Wnt5a receptor-actin-myosin-polarity
(WRAMP) structure", which integrates endosome-cytoskeleton interactions with mechanisms for cell polarity to
achieve a spatially restricted, rear-polarized elevation of actomyosin and cytosolic Ca2+. The goal of this project
is to characterize the mechanisms which explain how the WRAMP structure activates rear actomyosin and
Ca2+, and how it localizes to the rear to guide directional cell migration. The Specific Aims will address three
key objectives: Aim 1. Determine the protein interactions in WRAMP structures that induce actomyosin
contraction. This aim will test the hypothesis that MCAM and Wnt5a receptors, contained in a specific pool of
endosome vesicles, interact with cytosolic proteins to promote localized activation of RhoA and ROCK, which
in turn elevate actomyosin. Aim 2. Determine the signals responsible for cellular localization of the WRAMP
structure. This aim will test the hypothesis that the polarization of WRAMP structures involves endosome
trafficking along cortical microtubules, signaled by interactions between the plasma membrane binding protein,
ezrin, and the scaffold, IQGAP1. Aim 3. Investigate how the WRAMP structure promotes Ca2+ signaling. This
aim will test the hypothesis that the WRAMP structure elevates cytosolic Ca2+ by facilitating ER-PM contacts
and STIM-ORAI interactions. The project is innovative, because the WRAMP structure is an unexplored
cellular mechanism, which illustrates how intracellular positioning of organelles controls cytoskeletal
reorganization and cell polarity. The project also presents multidisciplinary strategies to analyze large
heterogeneous complexes, which like the WRAMP structure, involve many components and are temporally
and spatially dynamic, and therefore hard to analyze. Our project is supported by a wealth of preliminary data,
and integrates the expertise of many collaborators to address a cutting-edge, hypothesis-driven research
question. The outcomes will generate a conceptually new knowledge about basic mechanisms for symmetry
breaking, front-rear polarity, and cell migration.
Terms: <Actin-Activated ATPase><Actins><Actomyosin><Address><Adhesion Plaques><Adhesions><Adverse effects><Anti-Cancer Agents><Antineoplastic Agents><Antineoplastic Drugs><Antineoplastics><Automobile Driving><Basic Research><Basic Science><Binding Proteins><Blood Cells><CD146><Cancer Drug><Cancers><Cell Body><Cell Communication and Signaling><Cell Locomotion><Cell Migration><Cell Movement><Cell Polarity><Cell Signaling><Cell Surface Receptors><Cell membrane><Cell-Extracellular Matrix><Cell-Matrix Adherens Junctions><Cells><Cellular Matrix><Cellular Migration><Cellular Motility><Chicken Homolog of Gicerin><Colon Cancer><Colon Carcinoma><Colonic Carcinoma><Complex><Coupled><Cytoplasmic Membrane><Cytoskeletal Modeling><Cytoskeletal Organization><Cytoskeletal Organization Process><Cytoskeletal Reorganization><Cytoskeletal System><Cytoskeleton><Data><Development><ECM><Endosomes><Event><Extracellular Matrix><F-Actin><Filamentous Actin><Filopodia><Focal Adhesions><Focal Contacts><G-Proteins><GDP Dissociation Factor><GDP Dissociation Stimulators><GDP Exchange Factors><GDP-GTP Exchange Protein><GDP-GTP Reversing Factors><GTP GDP exchange factor><GTP-Binding Proteins><GTP-Regulatory Proteins><Gastric Body Cancer><Gastric Cancer><Gastric Cardia Cancer><Gastric Fundus Cancer><Gastric Pylorus Cancer><Goals><Guanine Nucleotide Coupling Protein><Guanine Nucleotide Exchange Factors><Guanine Nucleotide Exchange Protein><Guanine Nucleotide Regulatory Proteins><Guanine Nucleotide Releasing Factors><Guanyl-Nucleotide Exchange Factor><Guanyl-Nucleotide Releasing Factor><Inflammation><Intracellular Communication and Signaling><Intracellular Second Messenger><Investigation><Knowledge><Lead><Lifting><Ligand Binding Protein><Ligand Binding Protein Gene><Ligands><Link><Location><MCAM><MCAM gene><MUC18><Malignant Gastric Neoplasm><Malignant Gastric Tumor><Malignant Melanoma><Malignant Neoplasms><Malignant Ovarian Neoplasm><Malignant Ovarian Tumor><Malignant Pancreatic Neoplasm><Malignant Tumor><Malignant Tumor of the Lung><Malignant Tumor of the Ovary><Malignant neoplasm of lung><Malignant neoplasm of ovary><Malignant neoplasm of pancreas><Mediating><Melanoma Adhesion Molecule><Melanoma-Associated Glycoprotein MUC18><Membrane><Metastasis><Metastasize><Metastatic Lesion><Metastatic Mass><Metastatic Neoplasm><Metastatic Tumor><Micro-tubule><Microtubules><Motility><Movement><Myosin A><Myosin ATPase><Myosin Adenosine Triphosphatase><Myosin Adenosinetriphosphatase><Myosin B><Myosin IIA><Myosin IIB><Myosin Regulatory Light Chains><Myosins><Names><Neoplasm Metastasis><Neoplastic Disease Chemotherapeutic Agents><Non-Muscle Myosin Type IIA><Non-Muscle Myosin Type IIB><Nonmuscle Myosin Type IIA><Nonmuscle Myosin Type IIB><Organelles><Outcome><Ovary Cancer><Pancreas Cancer><Pancreatic Cancer><Pb element><Peripheral Blood Cell><Phosphorylation><Plasma Membrane><Position><Positioning Attribute><Process><Protein Binding><Protein Phosphorylation><Proteins><Public Health><Pulmonary Cancer><Pulmonary malignant Neoplasm><Receptor Protein><Receptosomes><Research><Rho-associated kinase><Rho-kinase><RhoGDI><STIM1><STIM1 gene><Second Messenger Systems><Second Messengers><Secondary Neoplasm><Secondary Tumor><Signal Pathway><Signal Transduction><Signal Transduction Systems><Signaling><Signaling Molecule><Stomach Cancer><Stromal Interaction Molecule 1><Structure><Tail><Testing><Therapeutic><Thyroid><Thyroid Gland><Thyroid Head and Neck><Tumor-Specific Treatment Agents><Vesicle><Work><angiogenesis><anti-cancer drug><anticancer agent><anticancer drug><biological signal transduction><body movement><bound protein><cancer in the colon><cancer metastasis><cell motility><cellular polarity><developmental><directional cell><driving><driving force><exchange factor><extracellular><ezrin><heavy metal Pb><heavy metal lead><human disease><inhibitor><inhibitor/antagonist><innovate><innovation><innovative><intracellular skeleton><lung cancer><malignancy><malignant stomach neoplasm><malignant stomach tumor><mechanical force><melanoma><membrane structure><membrane-organizing extension spike protein><migration><moesin><multidisciplinary><neoplasm/cancer><non-muscle myosin><nonmuscle myosin><novel><ovarian cancer><phosphoprotein p81><plasmalemma><polymerization><receptor><receptor internalization><recruit><rho GDI><rhoB p20 GDI><scaffold><scaffolding><sensor><signal transduction second messengers><stomach fundus cancer><stomach pylorus cancer><trafficking><tumor cell metastasis>