English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

The inositol 1,4,5-trisphosphate receptor (InsP3R) is the main calcium(Ca2+) release channel in most tissues. Three isoforms have been identified, but only types I and II InsP3R have been characterized. Here we examine the functional properties of the type III InsP3R because this receptor is restricted to the trigger zone from which Ca2+ waves originate and it has distinctive InsP3-binding properties. We find that type III InsP3R forms Ca2+ channels with single-channel currents that are similar to those of type I InsP3R; however, the open probability of type III InsP3R isoform increases monotonically with increased cytoplasmic Ca2+ concentration, whereas the type I isoform has a bell-shaped dependence on cytoplasmic Ca2+. The properties of type III InsP3R provide positive feedback as Ca2+ is released; the lack of negative feedback allows complete Ca2+ release from intracellular stores. Thus, activation of type III InsP3R in cells that express only this isoform results in a single transient, but global, increase in the concentration of cytosolic Ca2+. The bell-shaped Ca2+-dependence curve of type I InsP3R is ideal for supporting Ca2+ oscillations, whereas the properties of type III InsP3R are better suited to signal initiation.

Type III InsP3 receptor channel stays open in the presence of increased calcium