The pH sensibility of actin-bundling LIM proteins is governed by the acidic properties of their C-terminal domain.

  • Cytoskeleton and Cancer Progression
  • NORLUX Neuro-Oncology Laboratory
  • DNA Repair and Chemoresistance
August 19, 2015 By:
  • Moes D
  • Hoffmann C
  • Dieterle M
  • Moreau F
  • Neumann K
  • Papuga J
  • Furtado AT
  • Steinmetz A
  • Thomas C.

Actin-bundling Arabidopsis LIM proteins are subdivided into two subfamilies differing in their pH sensitivity. Widely-expressed WLIMs are active under low and high physiologically-relevant pH conditions, whereas pollen-enriched PLIMs are inactivated by pH values above 6.8. By a domain swapping approach we identified the C-terminal (Ct) domain of PLIMs as the domain responsible for pH responsiveness. Remarkably, this domain conferred pH sensitivity to LIM proteins, when provided "in trans" (i.e., as a single, independent, peptide), indicating that it operates through the interaction with another domain. An acidic 6xc-Myc peptide functionally mimicked the Ct domain of PLIMs and efficiently inhibited LIM actin bundling activity under high pH conditions. Together, our data suggest a model where PLIMs are regulated by an intermolecular interaction between their acidic Ct domain and another, yet unidentified, domain.

2015 Aug. FEBS Lett.589(18):2312-9. Epub 2015 Jul 29.
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