Reduced PaxillinB localization to cell-substrate adhesions promotes cell migration inDictyostelium

Abstract

AbstractMany cells adhere to extracellular matrix for efficient cell migration. This adhesion is mediated by focal adhesions, a protein complex linking the extracellular matrix to the intracellular cytoskeleton. Focal adhesions have been studied extensively in mesenchymal cells, but recent research in physiological contexts and amoeboid cells suggest focal adhesion regulation differs from the mesenchymal focal adhesion paradigm. We usedDictyostelium discoideumto uncover new mechanisms of focal adhesion regulation, asDictyosteliumare amoeboid cells that form focal adhesion-like structures for migration. We show that PaxillinB, theDictyosteliumhomologue of Paxillin, localizes to dynamic focal adhesion-like structures duringDictyosteliummigration. Unexpectedly, reduced PaxillinB recruitment to these structures increasesDictyosteliumcell migration. Quantitative analysis of focal adhesion size and dynamics show that lack of PaxillinB recruitment to focal adhesions does not alter focal adhesion size, but rather increases focal adhesion turnover. These findings are in direct contrast to Paxillin function at focal adhesions during mesenchymal migration, challenging the established focal adhesion model.Short SummaryFierro Morales et al. show that the role of PaxillinB in focal adhesion-based migration differs from the canonical mesenchymal focal adhesion paradigm.