Email updates

Keep up to date with the latest news and content from BMC Cell Biology and BioMed Central.

Open Access Highly Accessed Research article

Persistent directional cell migration requires ion transport proteins as direction sensors and membrane potential differences in order to maintain directedness

Nurdan Özkucur*, Srikanth Perike, Priyanka Sharma and Richard HW Funk

Author Affiliations

Department of Anatomy, Medical Faculty Carl Gustav Carus, Technical University of Dresden, Dresden, Germany

For all author emails, please log on.

BMC Cell Biology 2011, 12:4  doi:10.1186/1471-2121-12-4

Published: 22 January 2011

Abstract

Background

Ion transport proteins generate small electric fields that can induce directional cell motility; however, little is known about their mechanisms that lead to directedness. We investigated Na, K-ATPase (NaKA) and Na+/H+ exchanger isoforms (NHE1 and 3) in SaOS-2 and Calvarial osteoblasts, which present anode- and cathode- directed motility, during electrotaxis.

Results

Significant colocalizations of NaKA with vinculin and pNHE3 with ß-actin were observed to occur at the leading edges of cells. The directedness were attenuated when NaKA or NHE3 was inhibited, confirming their implication in directional sensing. Depending on the perceived direction, a divergent regulation in PIP2 levels as a function of NHE3 and NaKA levels was observed, suggesting that PIP2 may act as a spatiotemporal regulator of the cell membrane during electrotaxis. Moreover, at the same places where pNHE3 accumulates, bubble-shaped H+ clouds were observed, suggesting a physio-mechanical role for NHE3. The cell membrane becomes hyperpolarized at the front and depolarized at the back, which confirms NaKA activity at the leading edge.

Conclusion

We suggest a novel role for both NaKA and NHE3 that extends beyond ion translocation and conclude that they can act as directional sensors and Vmem as a regulatory cue which maintain the persistent direction in electrotaxis.