Skip to main content
eScholarship
Open Access Publications from the University of California

KCNJ15/Kir4.2 couples with polyamines to sense weak extracellular electric fields in galvanotaxis

  • Author(s): Nakajima, KI
  • Zhu, K
  • Sun, YH
  • Hegyi, B
  • Zeng, Q
  • Murphy, CJ
  • Small, JV
  • Chen-Izu, Y
  • Izumiya, Y
  • Penninger, JM
  • Zhao, M
  • et al.
Abstract

© 2015 Macmillan Publishers Limited. Weak electric fields guide cell migration, known as galvanotaxis/electrotaxis. The sensor(s) cells use to detect the fields remain elusive. Here we perform a large-scale screen using an RNAi library targeting ion transporters in human cells. We identify 18 genes that show either defective or increased galvanotaxis after knockdown. Knockdown of the KCNJ15 gene (encoding inwardly rectifying K + channel Kir4.2) specifically abolishes galvanotaxis, without affecting basal motility and directional migration in a monolayer scratch assay. Depletion of cytoplasmic polyamines, highly positively charged small molecules that regulate Kir4.2 function, completely inhibits galvanotaxis, whereas increase of intracellular polyamines enhances galvanotaxis in a Kir4.2-dependent manner. Expression of a polyamine-binding defective mutant of KCNJ15 significantly decreases galvanotaxis. Knockdown or inhibition of KCNJ15 prevents phosphatidylinositol 3,4,5-triphosphate (PIP 3) from distributing to the leading edge. Taken together these data suggest a previously unknown two-molecule sensing mechanism in which KCNJ15/Kir4.2 couples with polyamines in sensing weak electric fields.

Many UC-authored scholarly publications are freely available on this site because of the UC Academic Senate's Open Access Policy. Let us know how this access is important for you.

Main Content
Current View