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Characterization of two-pore channel 2 (TPCN2)-mediated Ca2+ currents in isolated lysosomes.

ABSTRACT: Two-pore channels (TPCNs) have been proposed to form lysosomal Ca(2+) release channels that are activated by nicotinic acid adenine dinucleotide phosphate. Here, we employ a glass chip-based method to record for the first time nicotinic acid adenine dinucleotide phosphate -dependent currents through a two-pore channel (TPCN2) from intact lysosomes. We show that TPCN2 is a highly selective Ca(2+) channel that is regulated by intralysosomal pH. Using site-directed mutagenesis, we identify an amino acid residue in the putative pore region that is crucial for conferring high Ca(2+) selectivity. Our glass chip-based method will provide electrophysiological access not only to lysosomal TPCN channels but also to a broad range of other intracellular ion channels.

SUBMITTER: Schieder M

PROVIDER: S-EPMC2898409 | biostudies-literature | 2010 Jul

REPOSITORIES: biostudies-literature

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Characterization of two-pore channel 2 (TPCN2)-mediated Ca2+ currents in isolated lysosomes.

Schieder Michael M Rötzer Katrin K Brüggemann Andrea A Biel Martin M Wahl-Schott Christian A CA

The Journal of biological chemistry 20100521 28

Two-pore channels (TPCNs) have been proposed to form lysosomal Ca(2+) release channels that are activated by nicotinic acid adenine dinucleotide phosphate. Here, we employ a glass chip-based method to record for the first time nicotinic acid adenine dinucleotide phosphate -dependent currents through a two-pore channel (TPCN2) from intact lysosomes. We show that TPCN2 is a highly selective Ca(2+) channel that is regulated by intralysosomal pH. Using site-directed mutagenesis, we identify an amino ...[more]

PMID: 20495006

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