Year: 2007
Type: article
Abstract: Although Ca(2+) release from early endosomes (EE) is important for the fusion of primary endosomes, the presence of an ion channel responsible for releasing calcium from the EE has not been shown. A recent proteomics study has identified the TRPV2 channel protein in EE, suggesting that transient receptor potential-like Ca(2+) channels may be in endosomes. The submicron size of endosomes has made it difficult to study their ion channels in the past. We have overcome this problem by generating enlarged EE with the help of a hydrolysis-deficient SKD1/VPS4B mutant in HEK293 cells. Here we report the first patch clamp recording of a novel endosome calcium channel (ECC) in these enlarged EE. The ECC shows a similar pharmacology to that of the TRPV2 channel. In addition, the ECC has a unique chloride-dependent regulation; it is inhibited by the endosome luminal chloride with a K(50) of 82 mm.
Source: Journal of Biological Chemistry
Institution: Washington University in St. Louis
Language: English
Topic: Ion Channels and Receptors
Subfield: Sensory Systems
Field: Neuroscience
Domain: Life Sciences
Open Access status: hybrid
Estimated APC paid: $3,430
OpenAlex ID: W2006033801