TitleA pH-independent DNA nanodevice for quantifying chloride transport in organelles of living cells.
Publication TypeJournal Article
Year of Publication2015
AuthorsSaha S, Prakash V, Halder S, Chakraborty K, Krishnan Y
JournalNat Nanotechnol
Date Published2015 Jul

The concentration of chloride ions in the cytoplasm and subcellular organelles of living cells spans a wide range (5-130 mM), and is tightly regulated by intracellular chloride channels or transporters. Chloride-sensitive protein reporters have been used to study the role of these chloride regulators, but they are limited to a small range of chloride concentrations and are pH-sensitive. Here, we show that a DNA nanodevice can precisely measure the activity and location of subcellular chloride channels and transporters in living cells in a pH-independent manner. The DNA nanodevice, called Clensor, is composed of sensing, normalizing and targeting modules, and is designed to localize within organelles along the endolysosomal pathway. It allows fluorescent, ratiometric sensing of chloride ions across the entire physiological regime. We used Clensor to quantitate the resting chloride concentration in the lumen of acidic organelles in Drosophila melanogaster. We showed that lumenal lysosomal chloride, which is implicated in various lysosomal storage diseases, is regulated by the intracellular chloride transporter DmClC-b.

Alternate JournalNat Nanotechnol
PubMed ID26098226
Grant ListP30 CA060553 / CA / NCI NIH HHS / United States
/ / Wellcome Trust / United Kingdom