TY - JOUR
T1 - Plakophilin 2 affects cell migration by modulating focal adhesion dynamics and integrin protein expression
AU - Koetsier, Jennifer L.
AU - Amargo, Evangeline V.
AU - Todorović, Viktor
AU - Green, Kathleen J.
AU - Godsel, Lisa M.
N1 - Funding Information:
We thank the members of the Green laboratory for their advice. We thank Dr Mary Beckerle for the kind gift of the zyxin polyclonal antibody. We thank Dr Teng-Leong Chew for the GFP-tagged vinculin and paxillin constructs, and for his advice on TIRF imaging and FRAP techniques and analysis. We thank Dr Rolf Sara, University of Turku, Finland, for the FRAPCalc program used for FRAP analysis. Imaging work was performed at the Northwestern University Cell Imaging Facility generously supported by CCSG P30 CA060553 awarded to the Robert H Lurie Comprehensive Cancer Center. FRAP and live-cell imaging was performed on the Andor spinning disk confocal purchased with the support of 1S10RR031680-01. Paul Hoover supplied primary keratinocyte cultures from the Northwestern University Skin Disease Research Center Keratinocyte Core Facility with support from National Institutes of Health/National Institute of Arthritis and Musculoskeletal and Skin Diseases (1P30AR057216-01). This work was supported by the Dermatology Foundation and the Skin Cancer Foundation to LMG and by National Institutes of Health grants to KJG (R37 AR043380).
PY - 2014/1
Y1 - 2014/1
N2 - Plakophilin 2 (PKP2), a desmosome component, modulates the activity and localization of the small GTPase RhoA at sites of cell-cell contact. PKP2 regulates cortical actin rearrangement during junction formation, and its loss is accompanied by an increase in actin stress fibers. We hypothesized that PKP2 may regulate focal adhesion dynamics and cell migration. Here we show that PKP2-deficient cells bind efficiently to the extracellular matrix, but upon spreading display total cell areas ∼30% smaller than control cells. Focal adhesions in PKP2-deficient cells are ∼2 × larger and more stable than in control cells, and vinculin displays an increased time for fluorescence recovery after photobleaching. Furthermore, β4 and β1 integrin protein and mRNA expression is elevated in PKP2-silenced cells. Normal focal adhesion phenotypes can be restored in PKP2-null cells by dampening the RhoA pathway or silencing β1 integrin. However, integrin expression levels are not restored by RhoA signaling inhibition. These data uncover a potential role for PKP2 upstream of β1 integrin and RhoA in integrating cell-cell and cell-substrate contact signaling in basal keratinocytes necessary for the morphogenesis, homeostasis, and reepithelialization of the stratified epidermis.
AB - Plakophilin 2 (PKP2), a desmosome component, modulates the activity and localization of the small GTPase RhoA at sites of cell-cell contact. PKP2 regulates cortical actin rearrangement during junction formation, and its loss is accompanied by an increase in actin stress fibers. We hypothesized that PKP2 may regulate focal adhesion dynamics and cell migration. Here we show that PKP2-deficient cells bind efficiently to the extracellular matrix, but upon spreading display total cell areas ∼30% smaller than control cells. Focal adhesions in PKP2-deficient cells are ∼2 × larger and more stable than in control cells, and vinculin displays an increased time for fluorescence recovery after photobleaching. Furthermore, β4 and β1 integrin protein and mRNA expression is elevated in PKP2-silenced cells. Normal focal adhesion phenotypes can be restored in PKP2-null cells by dampening the RhoA pathway or silencing β1 integrin. However, integrin expression levels are not restored by RhoA signaling inhibition. These data uncover a potential role for PKP2 upstream of β1 integrin and RhoA in integrating cell-cell and cell-substrate contact signaling in basal keratinocytes necessary for the morphogenesis, homeostasis, and reepithelialization of the stratified epidermis.
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U2 - 10.1038/jid.2013.266
DO - 10.1038/jid.2013.266
M3 - Article
C2 - 23884246
AN - SCOPUS:84891019616
VL - 134
SP - 112
EP - 122
JO - Journal of Investigative Dermatology
JF - Journal of Investigative Dermatology
SN - 0022-202X
IS - 1
ER -