The effect of mouse twinfilin-1 on the structure and dynamics of monomeric actin

Veronika Takács-Kollár; Miklós Nyitrai; Gábor Hild

doi:10.1016/j.bbapap.2016.04.002

The effect of mouse twinfilin-1 on the structure and dynamics of monomeric actin

Biochim Biophys Acta. 2016 Jul;1864(7):840-6. doi: 10.1016/j.bbapap.2016.04.002. Epub 2016 Apr 12.

Authors

Veronika Takács-Kollár¹, Miklós Nyitrai², Gábor Hild³

Affiliations

¹ University of Pécs, Medical School, Department of Biophysics, Pécs, Szigeti Str. 12, H-7624, Hungary.
² University of Pécs, Medical School, Department of Biophysics, Pécs, Szigeti Str. 12, H-7624, Hungary; Szentágothai Research Center, Pécs, Ifjúság Str. 34, H-7624, Hungary; MTA-PTE Nuclear-Mitochondrial Interactions Research Group, Pécs, Szigeti Str. 12, H-7624, Hungary.
³ University of Pécs, Medical School, Department of Biophysics, Pécs, Szigeti Str. 12, H-7624, Hungary; University of Pécs, Medical School, Department of Radiology, Pécs, Ifjúság Str. 13. H-7624, Hungary. Electronic address: gabor.hild@aok.pte.hu.

PMID: 27079635
DOI: 10.1016/j.bbapap.2016.04.002

Abstract

The effect of twinfilin-1 on the structure and dynamics of monomeric actin was investigated with fluorescence spectroscopy and differential scanning calorimetry experiments. Fluorescence anisotropy measurements proved that G-actin and twinfilin-1 could form a complex. Due to the formation of the complexes the dissociation of the nucleotide slowed down from the nucleotide-binding pocket of actin. Fluorescence quenching experiments showed that the accessibility of the actin bound ε-ATP decreased in the presence of twinfilin-1. Temperature dependent fluorescence resonance energy transfer and differential scanning calorimetry experiments revealed that the protein matrix of actin becomes more rigid and more heat resistant in the presence of twinfilin-1. The results suggest that the nucleotide binding cleft shifted into a more closed and stable conformational state of actin in the presence of twinfilin-1.

Keywords: Actin; Differential scanning calorimetry; Fluorescence spectroscopy; Mouse twinfilin-1.

Publication types

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

MeSH terms

Actins / chemistry*
Animals
Ethenoadenosine Triphosphate / metabolism
Fluorescence Resonance Energy Transfer
Mice
Microfilament Proteins / metabolism*
Spectrometry, Fluorescence
Temperature

Substances

Actins
Ethenoadenosine Triphosphate
Microfilament Proteins
Ptk9 protein, mouse