| First Author | Jamison J | Year | 2013 |
| Journal | PLoS One | Volume | 8 |
| Issue | 10 | Pages | e77434 |
| PubMed ID | 24155954 | Mgi Jnum | J:209094 |
| Mgi Id | MGI:5565656 | Doi | 10.1371/journal.pone.0077434 |
| Citation | Jamison J, et al. (2013) PKCdelta localization at the membrane increases matrix traction force dependent on PLCgamma1/EGFR signaling. PLoS One 8(10):e77434 |
| abstractText | INTRODUCTION: During wound healing, fibroblasts initially migrate into the wound bed and later contract the matrix. Relevant mediators of transcellular contractility revealed by systems analyses are protein kinase c delta/myosin light chain-2 (PKCdelta/MLC-2). PKCdelta is activated by growth factor-driven PLCgamma1 hydrolysis of phosphoinositide bisphosphate (PIP2) hydrolysis when it becomes tranlocated to the membrane. This leads to MLC-2 phosphorylation that regulates myosin for contractility. Furthermore, PKCdelta n-terminus mediates PKCdelta localization to the membrane in relative proximity to PLCgamma1 activity. However, the role this localization and the relationship to its activation and signaling of force is not well understood. Therefore, we investigated whether the membrane localization of PKCdelta mediates the transcellular contractility of fibroblasts. METHODS: To determine PKCdelta activation in targeted membrane locations in mouse fibroblast cells (NR6-WT), two PKCdelta constructs were generated; PKCdelta-CaaX with farnesylation moiety targeting PKCdelta to the membrane and PKCdelta-SaaX a non-targeting control. RESULTS: Increased mean cell force was observed before and during EGF stimulation in fibroblasts expressing membrane-targeted PKCdelta (PKCdelta-CaaX) when analyzed with 2D cell traction force and 3D compaction of collagen matrix. This effect was reduced in cells deficient in EGFR/PLCy1 signaling. In cells expressing non-membrane targeted PKCdelta (PKCdelta-SaaX), the cell force exerted outside the ECM (extracellular matrix) was less, but cell motility/speed/persistence was increased after EGF stimulation. Change in cell motility and increased force exertion was also preceded by change in cell morphology. Organization of actin stress fibers was also decreased as a result of increasing membrane targeting of PKCdelta. CONCLUSION: From these results membrane tethering of PKCdelta leads to increased force exertion on ECM. Furthermore, our data show PLCgamma1 regulation of PKCdelta, at least in part, drives transcellular contractility in fibroblasts. |
