| Literature DB >> 30532082 |
Nagarjun Narayanaswamy1,2, Kasturi Chakraborty3,4, Anand Saminathan1,2, Elizabeth Zeichner1, KaHo Leung1,2, John Devany5, Yamuna Krishnan6,7.
Abstract
It is extremely challenging to quantitate lumenal Ca2+ in acidic Ca2+ stores of the cell because all Ca2+ indicators are pH sensitive, and Ca2+ transport is coupled to pH in acidic organelles. We have developed a fluorescent DNA-based reporter, CalipHluor, that is targetable to specific organelles. By ratiometrically reporting lumenal pH and Ca2+ simultaneously, CalipHluor functions as a pH-correctable Ca2+ reporter. By targeting CalipHluor to the endolysosomal pathway, we mapped lumenal Ca2+ changes during endosomal maturation and found a surge in lumenal Ca2+ specifically in lysosomes. Using lysosomal proteomics and genetic analysis, we found that catp-6, a Caenorhabditis elegans homolog of ATP13A2, was responsible for lysosomal Ca2+ accumulation-an example of a lysosome-specific Ca2+ importer in animals. By enabling the facile quantification of compartmentalized Ca2+, CalipHluor can expand the understanding of subcellular Ca2+ importers.Entities:
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Year: 2018 PMID： 30532082 PMCID： PMC7107693 DOI： 10.1038/s41592-018-0232-7
Source DB: PubMed Journal: Nat Methods ISSN： 1548-7091 Impact factor: 28.547