In normal skin hemidesmosomes tether keratinocytes to the basement membrane zone. The integrin alpha6beta4 resides at the core of each hemidesmosome and stabilizes cell interaction with laminin-5 in the extracellular matrix. However, there is also evidence that a6b4 integrin is involved in cell migration.
In aim 1, we present preliminary data suggesting that specific keratinocyte migration behavior requires alpha6beta4 integrin which, through its ability to regulate the activity of the small GTPase Rac1 and the actin-severing protein cofilin, determines a specific organizational state of laminin-5 in the extracellular matrix. We propose to uncover precisely how beta4 integrin determines matrix organization, with a focus on dissecting signaling pathways leading to proper matrix assembly.
In aim 2 we will identify those residues in the cytoplasmic tail of the alpha6 integrin subunit that determine the way cells assemble their matrix and which regulate cell motility. In addition, in aim 2 we will assess whether the tetraspanin molecule CD151 modulates the activity of alpha6beta4 integrin using knockout cells derived from mice engineered to lack expression of this membrane molecule. We will also test the hypothesis that the integrin-associated tetraspanin CD151 regulates the ability of laminin-5 receptors to organize their ligand in the matrix of keratinocytes and we will assess whether CD151 modulates the dynamic properties of alpha6beta4 integrin complexes along the substratum-attached surface of cultured keratinocytes.
In aim 3 we propose to study epidermal cell migration on basement membranes assembled by wild type keratinocytes and keratinocytes lacking expression of alpha6 integrin, beta4 integrin or CD151 in vivo and in organotypic culture. The results from our three aims will provide mechanistic insight into how alpha6beta4 integrin heterodimers and their associated proteins contribute to tissue remodeling during wound healing and certain pathological conditions.

Agency
National Institute of Health (NIH)
Institute
National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS)
Type
Research Project (R01)
Project #
5R01AR054184-20
Application #
7880131
Study Section
Arthritis, Connective Tissue and Skin Study Section (ACTS)
Program Officer
Baker, Carl
Project Start
1988-04-01
Project End
2011-09-14
Budget Start
2010-07-01
Budget End
2011-09-14
Support Year
20
Fiscal Year
2010
Total Cost
$312,955
Indirect Cost
Name
Northwestern University at Chicago
Department
Anatomy/Cell Biology
Type
Schools of Medicine
DUNS #
005436803
City
Chicago
State
IL
Country
United States
Zip Code
60611
Colburn, Zachary T; Jones, Jonathan C R (2018) Complexes of ?6?4 integrin and vimentin act as signaling hubs to regulate epithelial cell migration. J Cell Sci 131:
Colburn, Zachary T; Jones, Jonathan C R (2017) ?6?4 Integrin Regulates the Collective Migration of Epithelial Cells. Am J Respir Cell Mol Biol 56:443-452
Jones, Jonathan C R; Kam, Chen Yuan; Harmon, Robert M et al. (2017) Intermediate Filaments and the Plasma Membrane. Cold Spring Harb Perspect Biol 9:
Hiroyasu, Sho; Stimac, Gregory P; Hopkinson, Susan B et al. (2017) Loss of ?-PIX inhibits focal adhesion disassembly and promotes keratinocyte motility via myosin light chain activation. J Cell Sci 130:2329-2343
Moazedi-Fuerst, Florentine C; Gruber, Gerald; Stradner, Martin H et al. (2016) Effect of Laminin-A4 inhibition on cluster formation of human osteoarthritic chondrocytes. J Orthop Res 34:419-26
Hiroyasu, Sho; Colburn, Zachary T; Jones, Jonathan C R (2016) A hemidesmosomal protein regulates actin dynamics and traction forces in motile keratinocytes. FASEB J 30:2298-310
Boykins, Lou G; Jones, Jonathan C R; EstraƱo, Carlos E et al. (2016) Pre-embedding Double-Label Immunoelectron Microscopy of Chemically Fixed Tissue Culture Cells. Methods Mol Biol 1474:217-32
Jones, Jonathan C R (2016) Pre- and Post-embedding Immunogold Labeling of Tissue Sections. Methods Mol Biol 1474:291-307
Shelden, Eric A; Colburn, Zachary T; Jones, Jonathan C R (2016) Focusing super resolution on the cytoskeleton. F1000Res 5:
Morales-Nebreda, Luisa I; Rogel, Micah R; Eisenberg, Jessica L et al. (2015) Lung-specific loss of ?3 laminin worsens bleomycin-induced pulmonary fibrosis. Am J Respir Cell Mol Biol 52:503-12

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