Functional characterization of Val60, a key residue involved in the membrane-oligomerization of fragaceatoxin C, an actinoporin from Actinia fragacea

Koldo Morante; Jose M M Caaveiro; Ana Rosa Viguera; Kouhei Tsumoto; Juan Manuel González-Mañas

doi:10.1016/j.febslet.2015.06.012

Functional characterization of Val60, a key residue involved in the membrane-oligomerization of fragaceatoxin C, an actinoporin from Actinia fragacea

FEBS Lett. 2015 Jul 8;589(15):1840-6. doi: 10.1016/j.febslet.2015.06.012. Epub 2015 Jun 19.

Authors

Koldo Morante¹, Jose M M Caaveiro², Ana Rosa Viguera³, Kouhei Tsumoto⁴, Juan Manuel González-Mañas⁵

Affiliations

¹ Biophysics Unit (CSIC, UPV/EHU), University of the Basque Country, P.O. Box 644, 48080 Bilbao, Spain; Department of Biochemistry and Molecular Biology, University of the Basque Country, P.O. Box 644, 48080 Bilbao, Spain; Department of Bioengineering, Graduate School of Engineering, The University of Tokyo, Minato-ku 108-8639, Tokyo, Japan.
² Department of Bioengineering, Graduate School of Engineering, The University of Tokyo, Minato-ku 108-8639, Tokyo, Japan.
³ Biophysics Unit (CSIC, UPV/EHU), University of the Basque Country, P.O. Box 644, 48080 Bilbao, Spain.
⁴ Department of Bioengineering, Graduate School of Engineering, The University of Tokyo, Minato-ku 108-8639, Tokyo, Japan; Medical Proteomics Laboratory, Institute of Medical Science, The University of Tokyo, Minato-ku 108-8639, Tokyo, Japan; Department of Medical Genome Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Minato-ku 108-8639, Tokyo, Japan.
⁵ Department of Biochemistry and Molecular Biology, University of the Basque Country, P.O. Box 644, 48080 Bilbao, Spain. Electronic address: juanmanuel.gonzalez@ehu.es.

PMID: 26096781
DOI: 10.1016/j.febslet.2015.06.012

Abstract

Actinoporins are pore-forming toxins produced by different sea anemones that self-assemble within the membranes of their target cells and compromise their function as a permeability barrier. The recently published three-dimensional structures of two oligomeric complexes formed by fragaceatoxin C point to Val60 as a key residue involved in the oligomerization of the functional pore. To gain insight into the mechanism of toxin oligomerization, different point mutations have been introduced at this position. Functional characterization of the muteins suggests that Val60 represents a hot-spot where the introduction of mutations hinders protein assembly and reduces the overall affinity for membranes.

Keywords: Lipid–protein interaction; Model membranes; Pore-forming toxins; Protein oligomerization.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Amino Acid Sequence
Animals
Calorimetry
Cnidarian Venoms / chemistry*
Molecular Sequence Data
Polymerization
Sea Anemones / chemistry*
Sequence Homology, Amino Acid
Valine / chemistry
Valine / physiology*

Substances

Cnidarian Venoms
fragaceatoxin C
Valine