A protein-coupled fluorescent probe for organelle-specific imaging of Na+

Ryo Taguchi, Takuya Terai, Tasuku Ueno, Toru Komatsu, Kenjiro Hanaoka, Yasuteru Urano

Research output: Contribution to journalArticlepeer-review

9 Citations (Scopus)


Intracellular sodium concentration plays important roles in many cellular processes, but methods to analyze dynamic change of [Na+] in organelles of interest are still lacking. To address this problem, controlled localization of fluorescent Na+ probes is a key issue. In this work, we developed a protein-coupled Na+-sensitive fluorescent probe, HaloNa-1, which covalently labelled a HaloTag protein expressed at specific organelles in living cells. Fluorescence intensity of HaloNa-1 increased by approximately three-fold when complexed with Na+, and the dissociation constant was within physiological range. Notably, by conjugating a fluorescent protein to the HaloTag protein and using it as internal standard, one can reduce unwanted variation of probe fluorescence due to different cell volume, HaloTag expression level, etc. With this technique, we could observe elevation of intracellular [Na+] after ionophore stimulation with higher reliability than conventional sensors. We believe our probe is potentially useful to understand Na+ dynamics inside cells.

Original languageEnglish
Pages (from-to)575-581
Number of pages7
JournalSensors and Actuators, B: Chemical
Publication statusPublished - 2018 Jul 15
Externally publishedYes


  • Cell imaging
  • Fluorescence probe
  • HaloTag
  • Protein labeling
  • Sodium ion

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Instrumentation
  • Condensed Matter Physics
  • Surfaces, Coatings and Films
  • Metals and Alloys
  • Electrical and Electronic Engineering
  • Materials Chemistry


Dive into the research topics of 'A protein-coupled fluorescent probe for organelle-specific imaging of Na+'. Together they form a unique fingerprint.

Cite this