Periodic Lamellipodial Contractions Correlate with Rearward Actin Waves

摘要: Cellular lamellipodia bind to the matrix and probe its rigidity through forces generated by rearward F-actin transport. Cells respond moving toward more rigid matrices using an unknown mechanism. In spreading migrating cells we find local periodic contractions of that depend on rigidity, fibronectin binding myosin light chain kinase (MLCK). These leave rows bound beta3-integrin paxillin while generating waves actin alpha-actinin MLCK. The period between corresponds time for move across lamellipodia. Shortening lamellipodial width activating cofilin decreased this proportionally. Increasing Rac signaling activation increased period. We propose bound, contraction-activated complex is transported locally from tip base lamellipodium, next contraction/extension cycle.